{"segment":[{"time":24,"part":[{"title":"\u0110i\u1ec1n d\u1ea5u v\u00e0 s\u1ed1 th\u00edch h\u1ee3p v\u00e0o ch\u1ed7 tr\u1ed1ng","title_trans":"","temp":"fill_the_blank","correct":[[[">"],["10"]]],"list":[{"point":5,"width":50,"content":"","type_input":"","ques":"Gi\u1ea3i b\u1ea5t ph\u01b0\u01a1ng tr\u00ecnh: $5x - 18 > 3x + 2$<br\/><b>\u0110\u00e1p \u00e1n:<\/b> $x$ _input_ _input_","hint":"","explain":"<span class='basic_left'>Ta c\u00f3:<br\/>$5x - 18 > 3x + 2$ <br\/> $\\Leftrightarrow 5x - 3x > 2 + 18$ <br\/>$\\Leftrightarrow 2x > 20 $<br\/>$\\Leftrightarrow 2x : 2 > 20 : 2 $<br\/>$\\Leftrightarrow x > 10 $<br\/>V\u1eady t\u1eadp nghi\u1ec7m c\u1ee7a b\u1ea5t ph\u01b0\u01a1ng tr\u00ecnh l\u00e0 $\\left\\{x \\mid x > 10\\right\\}$<br\/>D\u1ea5u v\u00e0 s\u1ed1 c\u1ea7n \u0111i\u1ec1n v\u00e0o \u00f4 tr\u1ed1ng l\u1ea7n l\u01b0\u1ee3t l\u00e0 <span class='basic_pink'>\">\"; $10$<\/span><\/span>"}]}],"id_ques":1121},{"time":24,"part":[{"title":"\u0110i\u1ec1n d\u1ea5u v\u00e0 s\u1ed1 th\u00edch h\u1ee3p v\u00e0o ch\u1ed7 tr\u1ed1ng","title_trans":"","temp":"fill_the_blank","correct":[[["<"],["-9"]]],"list":[{"point":5,"width":50,"content":"","type_input":"","ques":"Gi\u1ea3i b\u1ea5t ph\u01b0\u01a1ng tr\u00ecnh: $-3x + 6 > 24 - x$<br\/><b>\u0110\u00e1p \u00e1n:<\/b> $x$ _input_ _input_","hint":"","explain":"<span class='basic_left'><span class='basic_green'>H\u01b0\u1edbng d\u1eabn:<\/span><br\/>- Khi chuy\u1ec3n m\u1ed9t h\u1ea1ng t\u1eed c\u1ee7a b\u1ea5t ph\u01b0\u01a1ng tr\u00ecnh t\u1eeb v\u1ebf n\u00e0y sang v\u1ebf kia ta ph\u1ea3i \u0111\u1ed5i d\u1ea5u h\u1ea1ng t\u1eed \u0111\u00f3<br\/>- Khi nh\u00e2n hai v\u1ebf c\u1ee7a b\u1ea5t ph\u01b0\u01a1ng tr\u00ecnh v\u1edbi c\u00f9ng m\u1ed9t s\u1ed1 kh\u00e1c $0$, ta ph\u1ea3i:<br\/>+ Gi\u1eef nguy\u00ean chi\u1ec1u b\u1ea5t ph\u01b0\u01a1ng tr\u00ecnh n\u1ebfu s\u1ed1 \u0111\u00f3 d\u01b0\u01a1ng<br\/>+ \u0110\u1ed5i chi\u1ec1u b\u1ea5t ph\u01b0\u01a1ng tr\u00ecnh n\u1ebfu s\u1ed1 \u0111\u00f3 \u00e2m<\/span> <br\/><span class='basic_left'><span class='basic_green'>B\u00e0i gi\u1ea3i:<\/span><br\/>Ta c\u00f3:<br\/>$-3x + 6 > 24 - x$ <br\/> $\\Leftrightarrow -3x + x > 24 - 6$ <br\/>$\\Leftrightarrow -2x > 18 $<br\/>$\\Leftrightarrow -2x : (-2) < 18 : (-2) $<br\/>$\\Leftrightarrow x < -9 $<br\/>V\u1eady t\u1eadp nghi\u1ec7m c\u1ee7a b\u1ea5t ph\u01b0\u01a1ng tr\u00ecnh l\u00e0 $\\left\\{x \\mid x < -9\\right\\}$<br\/>D\u1ea5u v\u00e0 s\u1ed1 c\u1ea7n \u0111i\u1ec1n v\u00e0o \u00f4 tr\u1ed1ng l\u1ea7n l\u01b0\u1ee3t l\u00e0 <span class='basic_pink'>\"<\"; $-9$<\/span>"}]}],"id_ques":1122},{"time":24,"part":[{"title":"L\u1ef1a ch\u1ecdn \u0111\u00e1p \u00e1n \u0111\u00fang nh\u1ea5t","title_trans":"","temp":"multiple_choice","correct":[[2]],"list":[{"point":5,"ques":"<center><img src='https://www.luyenthi123.com/file/luyenthi123/lop8/toan/daiso/bai26/lv2/img\/3.jpg' \/><\/center><br\/>Gi\u1ea3i b\u1ea5t ph\u01b0\u01a1ng tr\u00ecnh $8x + 16 < -5x + 55$","select":[" A. $\\left\\{x \\mid x > 3\\right\\}$"," B. $\\left\\{x \\mid x < 3\\right\\}$","C. $\\left\\{x \\mid x > 13 \\right\\}$","D. $\\left\\{x \\mid x < 13 \\right\\}$"],"hint":"S\u1eed d\u1ee5ng quy t\u1eafc chuy\u1ec3n v\u1ebf v\u00e0 quy t\u1eafc nh\u00e2n ho\u1eb7c quy t\u1eafc chia v\u1edbi m\u1ed9t s\u1ed1 \u0111\u1ec3 gi\u1ea3i.","explain":"<span class='basic_left'>Ta c\u00f3 $8x + 16 < -5x + 55$<br\/>$\\Leftrightarrow 8x + 5x < 55 - 16$<br\/>$\\Leftrightarrow 13x < 39$<br\/>$\\Leftrightarrow 13x : 13 < 39 : 13$ <br\/>$\\Leftrightarrow x < 3$<br\/>V\u1eady t\u1eadp nghi\u1ec7m c\u1ee7a b\u1ea5t ph\u01b0\u01a1ng tr\u00ecnh l\u00e0 $\\left\\{x \\mid x < 3\\right\\}$ <br\/>\u0110\u00e1p \u00e1n \u0111\u00fang l\u00e0 <span class='basic_pink'>B. $\\left\\{x \\mid x < 3\\right\\}$<\/span><\/span>","column":2}]}],"id_ques":1123},{"time":24,"part":[{"title":"L\u1ef1a ch\u1ecdn \u0111\u00e1p \u00e1n \u0111\u00fang nh\u1ea5t","title_trans":"","temp":"multiple_choice","correct":[[3]],"list":[{"point":5,"ques":"<center><img src='https://www.luyenthi123.com/file/luyenthi123/lop8/toan/daiso/bai26/lv2/img\/3.jpg' \/><\/center><br\/>Gi\u1ea3i b\u1ea5t ph\u01b0\u01a1ng tr\u00ecnh $3(x + 6) > 12x - (x + 14)$","select":[" A. $\\left\\{x \\mid x > -4\\right\\}$"," B. $\\left\\{x \\mid x < -4\\right\\}$","C. $\\left\\{x \\mid x < 4 \\right\\}$","D. $\\left\\{x \\mid x > 4 \\right\\}$"],"hint":"S\u1eed d\u1ee5ng quy t\u1eafc chuy\u1ec3n v\u1ebf v\u00e0 quy t\u1eafc nh\u00e2n ho\u1eb7c quy t\u1eafc chia v\u1edbi m\u1ed9t s\u1ed1 \u0111\u1ec3 gi\u1ea3i.","explain":"<span class='basic_left'>Ta c\u00f3:<br\/> $3(x + 6) > 12x - (x + 14)$<br\/>$\\Leftrightarrow 3x + 18 > 12x - x - 14$<br\/>$\\Leftrightarrow 3x + 18 > 11x - 14$<br\/>$\\Leftrightarrow 11x - 3x < 18 + 14$ <br\/>$\\Leftrightarrow 8x < 32$<br\/>$\\Leftrightarrow 8x : 8 < 32 : 8$<br\/>$\\Leftrightarrow x < 4$<br\/>V\u1eady t\u1eadp nghi\u1ec7m c\u1ee7a b\u1ea5t ph\u01b0\u01a1ng tr\u00ecnh l\u00e0 $\\left\\{x \\mid x < 4\\right\\}$ <br\/>\u0110\u00e1p \u00e1n \u0111\u00fang l\u00e0 <span class='basic_pink'>C. $\\left\\{x \\mid x < 4\\right\\}$<\/span><\/span>","column":2}]}],"id_ques":1124},{"time":24,"part":[{"title":"L\u1ef1a ch\u1ecdn \u0111\u00e1p \u00e1n \u0111\u00fang nh\u1ea5t","title_trans":"","temp":"multiple_choice","correct":[[3]],"list":[{"point":5,"ques":"<span class='basic_left'><center><img src='https://www.luyenthi123.com/file/luyenthi123/lop8/toan/daiso/bai26/lv2/img\/5.jpg' \/><\/center> T\u00ecm c\u00e1c nghi\u1ec7m nguy\u00ean d\u01b0\u01a1ng c\u1ee7a b\u1ea5t ph\u01b0\u01a1ng tr\u00ecnh: $15 - 3x \\geq 0$<\/span>","select":[" A. $x \\in \\left\\{1; 2; 3; 4\\right\\}$"," B. $x \\in \\left\\{ 2; 3; 4; 5\\right\\}$","C. $x \\in \\left\\{1; 2; 3; 4; 5\\right\\}$","D. $x \\in \\left\\{0; 1; 2; 3; 4; 5\\right\\}$"],"hint":"S\u1eed d\u1ee5ng quy t\u1eafc chuy\u1ec3n v\u1ebf v\u00e0 quy t\u1eafc nh\u00e2n v\u1edbi m\u1ed9t s\u1ed1 \u0111\u1ec3 gi\u1ea3i b\u1ea5t ph\u01b0\u01a1ng tr\u00ecnh t\u1eeb \u0111\u00f3 t\u00ecm ra k\u1ebft qu\u1ea3 c\u1ea7n t\u00ecm.","explain":"<span class='basic_left'>Ta c\u00f3 $15 - 3x \\geq 0$<br\/>$\\Leftrightarrow 3x \\leq 15$<br\/>$\\Leftrightarrow x \\leq 15 : 3$<br\/>$\\Leftrightarrow x \\leq 5$<br\/>V\u1eady c\u00e1c nghi\u1ec7m nguy\u00ean d\u01b0\u01a1ng c\u1ee7a b\u1ea5t ph\u01b0\u01a1ng tr\u00ecnh l\u00e0 $x \\in \\left\\{1; 2; 3; 4; 5\\right\\}$ <br\/>\u0110\u00e1p \u00e1n \u0111\u00fang l\u00e0 <span class='basic_pink'>C.$x \\in \\left\\{1; 2; 3; 4; 5\\right\\}$<\/span><\/span>","column":2}]}],"id_ques":1125},{"time":24,"part":[{"title":"L\u1ef1a ch\u1ecdn \u0111\u00e1p \u00e1n \u0111\u00fang nh\u1ea5t","title_trans":"","temp":"multiple_choice","correct":[[2]],"list":[{"point":5,"ques":"<span class='basic_left'><center><img src='https://www.luyenthi123.com/file/luyenthi123/lop8/toan/daiso/bai26/lv2/img\/6.jpg' \/><\/center> T\u00ecm c\u00e1c nghi\u1ec7m nguy\u00ean \u00e2m c\u1ee7a b\u1ea5t ph\u01b0\u01a1ng tr\u00ecnh: $4x + 12 \\geq 0$<\/span>","select":[" A. $x \\in \\left\\{-2; -1\\right\\}$"," B. $x \\in \\left\\{ -3; -2; -1\\right\\}$","C. $x \\in \\left\\{-3; -2; -1; 0\\right\\}$","D. $x \\in \\left\\{-4; -3; -2; -1\\right\\}$"],"hint":"S\u1eed d\u1ee5ng quy t\u1eafc chuy\u1ec3n v\u1ebf v\u00e0 quy t\u1eafc nh\u00e2n v\u1edbi m\u1ed9t s\u1ed1 \u0111\u1ec3 gi\u1ea3i b\u1ea5t ph\u01b0\u01a1ng tr\u00ecnh t\u1eeb \u0111\u00f3 t\u00ecm ra k\u1ebft qu\u1ea3 c\u1ea7n t\u00ecm.","explain":"<span class='basic_left'>Ta c\u00f3 $4x + 12 \\geq 0$<br\/>$\\Leftrightarrow 4x \\geq -12$<br\/>$\\Leftrightarrow x \\geq -12 : 4$<br\/>$\\Leftrightarrow x \\geq -3$<br\/>V\u1eady c\u00e1c nghi\u1ec7m nguy\u00ean \u00e2m c\u1ee7a b\u1ea5t ph\u01b0\u01a1ng tr\u00ecnh l\u00e0 $x \\in \\left\\{-3; -2; -1\\right\\}$ <br\/>\u0110\u00e1p \u00e1n \u0111\u00fang l\u00e0 <span class='basic_pink'>B.$x \\in \\left\\{-3; -2; -1\\right\\}$<\/span><\/span>","column":2}]}],"id_ques":1126},{"time":24,"part":[{"title":"L\u1ef1a ch\u1ecdn \u0111\u00e1p \u00e1n \u0111\u00fang nh\u1ea5t","title_trans":"","temp":"multiple_choice","correct":[[3]],"list":[{"point":5,"ques":"<span class='basic_left'><center><img src='https://www.luyenthi123.com/file/luyenthi123/lop8/toan/daiso/bai26/lv2/img\/6.jpg' \/><\/center> T\u00ecm c\u00e1c nghi\u1ec7m nguy\u00ean \u00e2m c\u1ee7a b\u1ea5t ph\u01b0\u01a1ng tr\u00ecnh: $5x + 30 \\geq -5$<\/span>","select":[" A. $x \\in \\left\\{-7; -6; -5; -4; -3; -2\\right\\}$"," B. $x \\in \\left\\{-6; -5; -4; -3; -2; -1\\right\\}$","C. $x \\in \\left\\{-7; -6; -5; -4; -3; -2; -1\\right\\}$","D. $x \\in \\left\\{-5; -4; -3; -2; -1\\right\\}$"],"hint":"S\u1eed d\u1ee5ng quy t\u1eafc chuy\u1ec3n v\u1ebf v\u00e0 quy t\u1eafc nh\u00e2n v\u1edbi m\u1ed9t s\u1ed1 \u0111\u1ec3 gi\u1ea3i b\u1ea5t ph\u01b0\u01a1ng tr\u00ecnh t\u1eeb \u0111\u00f3 t\u00ecm ra k\u1ebft qu\u1ea3 c\u1ea7n t\u00ecm.","explain":"<span class='basic_left'>Ta c\u00f3 $5x + 30 \\geq -5$<br\/>$\\Leftrightarrow 5x \\geq -5 - 30$<br\/>$\\Leftrightarrow 5x \\geq -35$<br\/>$\\Leftrightarrow x \\geq -35 : 5$<br\/>$\\Leftrightarrow x \\geq -7$<br\/>V\u1eady c\u00e1c nghi\u1ec7m nguy\u00ean \u00e2m c\u1ee7a b\u1ea5t ph\u01b0\u01a1ng tr\u00ecnh l\u00e0 $x \\in \\left\\{-7; -6; -5; -4; -3; -2; -1\\right\\}$ <br\/>\u0110\u00e1p \u00e1n \u0111\u00fang l\u00e0 <span class='basic_pink'>C.$x \\in \\left\\{-7; -6; -5; -4; -3; -2; -1\\right\\}$<\/span><\/span>","column":2}]}],"id_ques":1127},{"time":24,"part":[{"title":"L\u1ef1a ch\u1ecdn \u0111\u00e1p \u00e1n \u0111\u00fang nh\u1ea5t","title_trans":"","temp":"multiple_choice","correct":[[1]],"list":[{"point":5,"ques":"<span class='basic_left'><center><img src='https://www.luyenthi123.com/file/luyenthi123/lop8/toan/daiso/bai26/lv2/img\/5.jpg' \/><\/center> T\u00ecm c\u00e1c nghi\u1ec7m nguy\u00ean d\u01b0\u01a1ng c\u1ee7a b\u1ea5t ph\u01b0\u01a1ng tr\u00ecnh: $12 - 6x \\geq 3$<\/span>","select":[" A. $x = 1$"," B. $x \\in \\left\\{ 2; 3\\right\\}$","C. $x \\in \\left\\{1; 2; 3\\right\\}$","D. $x \\in \\left\\{0; 1; 2\\right\\}$"],"hint":"S\u1eed d\u1ee5ng quy t\u1eafc chuy\u1ec3n v\u1ebf v\u00e0 quy t\u1eafc nh\u00e2n v\u1edbi m\u1ed9t s\u1ed1 \u0111\u1ec3 gi\u1ea3i b\u1ea5t ph\u01b0\u01a1ng tr\u00ecnh t\u1eeb \u0111\u00f3 t\u00ecm ra k\u1ebft qu\u1ea3 c\u1ea7n t\u00ecm.","explain":"<span class='basic_left'>Ta c\u00f3 $12 - 6x \\geq 3$<br\/>$\\Leftrightarrow 6x \\leq 12 - 3$<br\/>$\\Leftrightarrow 6x \\leq 9$<br\/>$\\Leftrightarrow x \\leq 9 : 6$<br\/>$\\Leftrightarrow x \\leq 1,5$<br\/>V\u1eady nghi\u1ec7m nguy\u00ean d\u01b0\u01a1ng c\u1ee7a b\u1ea5t ph\u01b0\u01a1ng tr\u00ecnh l\u00e0 $x = 1$ <br\/>\u0110\u00e1p \u00e1n \u0111\u00fang l\u00e0 <span class='basic_pink'>A.$x = 1$<\/span><\/span>","column":2}]}],"id_ques":1128},{"time":24,"part":[{"title":"L\u1ef1a ch\u1ecdn \u0111\u00e1p \u00e1n \u0111\u00fang nh\u1ea5t","title_trans":"","temp":"multiple_choice","correct":[[2]],"list":[{"point":5,"ques":"<span class='basic_left'><center><img src='https://www.luyenthi123.com/file/luyenthi123/lop8/toan/daiso/bai26/lv2/img\/5.jpg' \/><\/center> Trong c\u00e1c b\u1ea5t ph\u01b0\u01a1ng tr\u00ecnh b\u1eadc nh\u1ea5t m\u1ed9t \u1ea9n sau \u0111\u00e2y, $x = 5$ l\u00e0 nghi\u1ec7m c\u1ee7a b\u1ea5t ph\u01b0\u01a1ng tr\u00ecnh n\u00e0o ?<\/span>","select":[" A. $2x + 5 > 16$"," B. $x - 7 < 2x - 9$","C. $2x + 1 < 3x - 8$","D. $x - 2 < 2x - 10$"],"hint":"Thay $x = 5$ v\u00e0o t\u1eebng b\u1ea5t ph\u01b0\u01a1ng tr\u00ecnh \u0111\u1ec3 ki\u1ec3m tra.","explain":"<span class='basic_left'>+ Thay $x = 5$ v\u00e0o b\u1ea5t ph\u01b0\u01a1ng tr\u00ecnh $2x + 5 > 16$ ta \u0111\u01b0\u1ee3c:<br\/>$2.5 + 5 > 16 \\Leftrightarrow 15 > 16$ (v\u00f4 l\u00fd)<br\/>$\\Rightarrow x = 5$ kh\u00f4ng l\u00e0 nghi\u1ec7m c\u1ee7a b\u1ea5t ph\u01b0\u01a1ng tr\u00ecnh $2x + 5 > 16$<br\/>+ Thay $x = 5$ v\u00e0o b\u1ea5t ph\u01b0\u01a1ng tr\u00ecnh $x - 7 < 2x - 9$, ta \u0111\u01b0\u1ee3c:<br\/>$5 - 7 < 2.5 - 9 \\Leftrightarrow -2 < 1$ (lu\u00f4n \u0111\u00fang)<br\/>$\\Rightarrow x = 5$ l\u00e0 nghi\u1ec7m c\u1ee7a b\u1ea5t ph\u01b0\u01a1ng tr\u00ecnh $x - 7 < 2x - 9$<br\/>+ Thay $x = 5$ v\u00e0o b\u1ea5t ph\u01b0\u01a1ng tr\u00ecnh $2x + 1 < 3x - 8$, ta \u0111\u01b0\u1ee3c:<br\/>$2.5 + 1 < 3.5 - 8 \\Leftrightarrow 11 < 7$ (v\u00f4 l\u00fd)<br\/>$\\Rightarrow x = 5$ kh\u00f4ng l\u00e0 nghi\u1ec7m c\u1ee7a b\u1ea5t ph\u01b0\u01a1ng tr\u00ecnh $2x + 1 < 3x - 8$<br\/>+ Thay $x = 5$ v\u00e0o b\u1ea5t ph\u01b0\u01a1ng tr\u00ecnh $x - 2 < 2x - 10$ ta \u0111\u01b0\u1ee3c:<br\/> $5 - 2 < 2.5 - 10 \\Leftrightarrow 3 < 0$ (v\u00f4 l\u00fd)<br\/>$\\Rightarrow x = 5$ kh\u00f4ng l\u00e0 nghi\u1ec7m c\u1ee7a b\u1ea5t ph\u01b0\u01a1ng tr\u00ecnh $x - 2 < 2x - 10$<br\/>V\u1eady ta ch\u1ecdn \u0111\u00e1p \u00e1n \u0111\u00fang l\u00e0 <span class='basic_pink'>B. $x - 7 < 2x - 9$<\/span> <\/span><br\/><span class='basic_left'><span class='basic_green'>Nh\u1eadn x\u00e9t:<\/span><br\/> Ngo\u00e0i c\u00e1ch l\u00e0m tr\u00ean ta c\u00f3 th\u1ec3 th\u1ef1c hi\u1ec7n gi\u1ea3i t\u1eebng b\u1ea5t ph\u01b0\u01a1ng tr\u00ecnh, t\u1eeb \u0111\u00f3 t\u00ecm ra \u0111\u00e1p \u00e1n c\u1ea7n t\u00ecm<\/span> <br\/><br\/>","column":2}]}],"id_ques":1129},{"time":24,"part":[{"title":"L\u1ef1a ch\u1ecdn \u0111\u00e1p \u00e1n \u0111\u00fang nh\u1ea5t","title_trans":"","temp":"multiple_choice","correct":[[4]],"list":[{"point":5,"ques":"<span class='basic_left'><center><img src='https://www.luyenthi123.com/file/luyenthi123/lop8/toan/daiso/bai26/lv2/img\/5.jpg' \/><\/center> Trong c\u00e1c b\u1ea5t ph\u01b0\u01a1ng tr\u00ecnh b\u1eadc nh\u1ea5t m\u1ed9t \u1ea9n sau \u0111\u00e2y, $x = -8$ l\u00e0 nghi\u1ec7m c\u1ee7a b\u1ea5t ph\u01b0\u01a1ng tr\u00ecnh n\u00e0o?<\/span>","select":[" A. $x + 3 > -4$"," B. $x - 3 < 2x + 4$","C. $3 - 2x > 5x + 59$","D. $x - 2 < -x - 10$"],"hint":"Thay $x = -8$ v\u00e0o t\u1eebng b\u1ea5t ph\u01b0\u01a1ng tr\u00ecnh \u0111\u1ec3 ki\u1ec3m tra.","explain":"<span class='basic_left'>+ Thay $x = -8$ v\u00e0o b\u1ea5t ph\u01b0\u01a1ng tr\u00ecnh $x + 3 > -4$ ta \u0111\u01b0\u1ee3c:<br\/>$-8 + 3 > -4 \\Leftrightarrow -5 > -4$ (v\u00f4 l\u00fd)<br\/>$\\Rightarrow x = -8$ kh\u00f4ng l\u00e0 nghi\u1ec7m c\u1ee7a b\u1ea5t ph\u01b0\u01a1ng tr\u00ecnh $x + 3 > -4$<br\/>+ Thay $x = -8$ v\u00e0o b\u1ea5t ph\u01b0\u01a1ng tr\u00ecnh $x - 3 < 2x + 4$, ta \u0111\u01b0\u1ee3c:<br\/>$-8 - 3 < 2.(-8) + 4 \\Leftrightarrow -11 < -12$ (v\u00f4 l\u00fd)<br\/>$\\Rightarrow x = -8$ kh\u00f4ng l\u00e0 nghi\u1ec7m c\u1ee7a b\u1ea5t ph\u01b0\u01a1ng tr\u00ecnh $x - 3 < 2x + 4$<br\/>+ Thay $x = -8$ v\u00e0o b\u1ea5t ph\u01b0\u01a1ng tr\u00ecnh $3 - 2x > 5x + 59$, ta \u0111\u01b0\u1ee3c:<br\/>$3 - 2.(-8) > 5.(-8) + 59 \\Leftrightarrow 19 > 19$ (v\u00f4 l\u00fd)<br\/>$\\Rightarrow x = -8$ kh\u00f4ng l\u00e0 nghi\u1ec7m c\u1ee7a b\u1ea5t ph\u01b0\u01a1ng tr\u00ecnh $3 - 2x > 5x + 59$<br\/>+ Thay $x = -8$ v\u00e0o b\u1ea5t ph\u01b0\u01a1ng tr\u00ecnh $x - 2 < -x - 10$ ta \u0111\u01b0\u1ee3c:<br\/> $-8 - 2 < -(-8) - 10 \\Leftrightarrow -10 < -2$ (lu\u00f4n \u0111\u00fang)<br\/>$\\Rightarrow x = -8$ l\u00e0 nghi\u1ec7m c\u1ee7a b\u1ea5t ph\u01b0\u01a1ng tr\u00ecnh $x - 2 < -x - 10$<br\/>V\u1eady ta ch\u1ecdn \u0111\u00e1p \u00e1n \u0111\u00fang l\u00e0 <span class='basic_pink'>D. $x - 2 < -x - 10$<\/span> <\/span><br\/><span class='basic_left'><span class='basic_green'>Nh\u1eadn x\u00e9t:<\/span><br\/> Ngo\u00e0i c\u00e1ch l\u00e0m tr\u00ean ta c\u00f3 th\u1ec3 th\u1ef1c hi\u1ec7n gi\u1ea3i t\u1eebng b\u1ea5t ph\u01b0\u01a1ng tr\u00ecnh, t\u1eeb \u0111\u00f3 t\u00ecm ra \u0111\u00e1p \u00e1n c\u1ea7n t\u00ecm<\/span> <br\/><br\/>","column":2}]}],"id_ques":1130},{"time":24,"part":[{"title":"L\u1ef1a ch\u1ecdn \u0111\u00e1p \u00e1n \u0111\u00fang nh\u1ea5t","title_trans":"","temp":"multiple_choice","correct":[[1]],"list":[{"point":5,"ques":"<span class='basic_left'><center><img src='https://www.luyenthi123.com/file/luyenthi123/lop8/toan/daiso/bai26/lv2/img\/5.jpg' \/><\/center> Trong c\u00e1c b\u1ea5t ph\u01b0\u01a1ng tr\u00ecnh b\u1eadc nh\u1ea5t m\u1ed9t \u1ea9n sau \u0111\u00e2y, $x = -12$ l\u00e0 nghi\u1ec7m c\u1ee7a b\u1ea5t ph\u01b0\u01a1ng tr\u00ecnh n\u00e0o ?<\/span>","select":[" A. $-x + 7 > 18$"," B. $2x + 4 < -21$","C. $x - 3 > -14$","D. $5 + 3x <-32$"],"hint":"Thay $x = -12$ v\u00e0o t\u1eebng b\u1ea5t ph\u01b0\u01a1ng tr\u00ecnh \u0111\u1ec3 ki\u1ec3m tra.","explain":"<span class='basic_left'>Ta c\u00f3:<br\/>+ Thay $x = -12$ v\u00e0o b\u1ea5t ph\u01b0\u01a1ng tr\u00ecnh $-x + 7 > 18$ ta \u0111\u01b0\u1ee3c:<br\/>$-(-12) + 7 > 18 \\Leftrightarrow 19 > 18$ (lu\u00f4n \u0111\u00fang)<br\/>$\\Rightarrow x = -12$ l\u00e0 nghi\u1ec7m c\u1ee7a b\u1ea5t ph\u01b0\u01a1ng tr\u00ecnh $-x + 7 > 18$<br\/>+ Thay $x = -12$ v\u00e0o b\u1ea5t ph\u01b0\u01a1ng tr\u00ecnh $2x + 4 < -21$, ta \u0111\u01b0\u1ee3c:<br\/>$2.(-12) + 4 < -21 \\Leftrightarrow -20 < -21$ (v\u00f4 l\u00fd)<br\/>$\\Rightarrow x = -12$ kh\u00f4ng l\u00e0 nghi\u1ec7m c\u1ee7a b\u1ea5t ph\u01b0\u01a1ng tr\u00ecnh $2x + 4 < -21$<br\/>+ Thay $x = -12$ v\u00e0o b\u1ea5t ph\u01b0\u01a1ng tr\u00ecnh $x - 3 > -14$, ta \u0111\u01b0\u1ee3c:<br\/>$-12 - 3 > -14 \\Leftrightarrow -15 > -14$ (v\u00f4 l\u00fd)<br\/>$\\Rightarrow x = -12$ kh\u00f4ng l\u00e0 nghi\u1ec7m c\u1ee7a b\u1ea5t ph\u01b0\u01a1ng tr\u00ecnh $x - 3 > -14$<br\/>+ Thay $x = -12$ v\u00e0o b\u1ea5t ph\u01b0\u01a1ng tr\u00ecnh $5 + 3x < -32$ ta \u0111\u01b0\u1ee3c:<br\/> $5 + 3.(-12) < -32 \\Leftrightarrow -31 < -32$ (v\u00f4 l\u00fd)<br\/>$\\Rightarrow x = -12$ kh\u00f4ng l\u00e0 nghi\u1ec7m c\u1ee7a b\u1ea5t ph\u01b0\u01a1ng tr\u00ecnh $5 + 3x < -32$<br\/>V\u1eady ta ch\u1ecdn \u0111\u00e1p \u00e1n \u0111\u00fang l\u00e0 <span class='basic_pink'> A. $-x + 7 > 18$<\/span> <\/span><br\/><span class='basic_left'><span class='basic_green'>Nh\u1eadn x\u00e9t:<\/span><br\/> Ngo\u00e0i c\u00e1ch l\u00e0m tr\u00ean ta c\u00f3 th\u1ec3 th\u1ef1c hi\u1ec7n gi\u1ea3i t\u1eebng b\u1ea5t ph\u01b0\u01a1ng tr\u00ecnh, t\u1eeb \u0111\u00f3 t\u00ecm ra \u0111\u00e1p \u00e1n c\u1ea7n t\u00ecm<\/span> <br\/><br\/>","column":2}]}],"id_ques":1131},{"time":24,"part":[{"title":"L\u1ef1a ch\u1ecdn \u0111\u00e1p \u00e1n \u0111\u00fang nh\u1ea5t","title_trans":"","temp":"multiple_choice","correct":[[1]],"list":[{"point":5,"ques":"<span class='basic_left'><center><img src='https://www.luyenthi123.com/file/luyenthi123/lop8/toan/daiso/bai26/lv2/img\/5.jpg' \/><\/center> B\u1ea5t ph\u01b0\u01a1ng tr\u00ecnh $x^2 + 4x + 4 \\geq 0$ c\u00f3 nghi\u1ec7m v\u1edbi m\u1ecdi $x$. <b>\u0110\u00fang<\/b> hay <b> Sai<\/b>?<\/span>","select":[" A. \u0110\u00fang"," B. Sai"],"hint":"","explain":"<span class='basic_left'><span class='basic_green'>Ph\u01b0\u01a1ng ph\u00e1p gi\u1ea3i:<\/span><br\/>Bi\u1ebfn \u0111\u1ed5i b\u1ea5t ph\u01b0\u01a1ng tr\u00ecnh v\u1ec1 d\u1ea1ng $\\left[f(x)\\right]^2 + k > 0$ (v\u1edbi $k > 0$)<\/span> <br\/><span class='basic_left'><span class='basic_green'>B\u00e0i gi\u1ea3i:<\/span><br\/>Ta c\u00f3: $x^2 + 4x + 4 = (x + 2)^2$<br\/>V\u00ec $(x + 2)^2 \\geq 0$ v\u1edbi m\u1ecdi $x$ <br\/>N\u00ean $x^2 + 4x + 4 \\geq 0$ c\u00f3 nghi\u1ec7m v\u1edbi m\u1ecdi gi\u00e1 tr\u1ecb $x$<br\/>Ta ch\u1ecdn \u0111\u00e1p \u00e1n: <span class='basic_pink'>A. \u0110\u00fang<\/span><\/span> <br\/><\/span><br\/>","column":2}]}],"id_ques":1132},{"time":24,"part":[{"title":"L\u1ef1a ch\u1ecdn \u0111\u00e1p \u00e1n \u0111\u00fang nh\u1ea5t","title_trans":"","temp":"multiple_choice","correct":[[1]],"list":[{"point":5,"ques":"<span class='basic_left'><center><img src='https://www.luyenthi123.com/file/luyenthi123/lop8/toan/daiso/bai26/lv2/img\/5.jpg' \/><\/center> B\u1ea5t ph\u01b0\u01a1ng tr\u00ecnh $x^2 - 6x + 9 \\geq 0$ c\u00f3 nghi\u1ec7m v\u1edbi m\u1ecdi $x$. <b>\u0110\u00fang<\/b> hay <b> Sai<\/b>?<\/span>","select":[" A. \u0110\u00fang"," B. Sai"],"hint":"","explain":"<span class='basic_left'><span class='basic_green'>Ph\u01b0\u01a1ng ph\u00e1p gi\u1ea3i:<\/span><br\/>Bi\u1ebfn \u0111\u1ed5i b\u1ea5t ph\u01b0\u01a1ng tr\u00ecnh v\u1ec1 d\u1ea1ng $\\left[f(x)\\right]^2 + k > 0$ (v\u1edbi $k > 0$)<\/span> <br\/><span class='basic_left'><span class='basic_green'>B\u00e0i gi\u1ea3i:<\/span><br\/>Ta c\u00f3: $x^2 -6x + 9 = (x - 3)^2$<br\/>L\u1ea1i c\u00f3: $(x - 3)^2 \\geq 0$ v\u1edbi m\u1ecdi $x$ <br\/>Suy ra $x^2 -6x + 9 \\geq 0$ c\u00f3 nghi\u1ec7m v\u1edbi m\u1ecdi gi\u00e1 tr\u1ecb $x$<br\/>Ta ch\u1ecdn \u0111\u00e1p \u00e1n: <span class='basic_pink'>A. \u0110\u00fang<\/span><\/span> <br\/><\/span><br\/>","column":2}]}],"id_ques":1133},{"time":24,"part":[{"title":"L\u1ef1a ch\u1ecdn \u0111\u00e1p \u00e1n \u0111\u00fang nh\u1ea5t","title_trans":"","temp":"multiple_choice","correct":[[2]],"list":[{"point":5,"ques":"<span class='basic_left'><center><img src='https://www.luyenthi123.com/file/luyenthi123/lop8/toan/daiso/bai26/lv2/img\/5.jpg' \/><\/center> B\u1ea5t ph\u01b0\u01a1ng tr\u00ecnh $x^2 - 12x + 36 < 0$ c\u00f3 nghi\u1ec7m v\u1edbi m\u1ecdi $x$. <b>\u0110\u00fang<\/b> hay <b> Sai<\/b>?<\/span>","select":[" A. \u0110\u00fang"," B. Sai"],"hint":"","explain":"<span class='basic_left'><span class='basic_green'>Ph\u01b0\u01a1ng ph\u00e1p gi\u1ea3i:<\/span><br\/>Bi\u1ebfn \u0111\u1ed5i b\u1ea5t ph\u01b0\u01a1ng tr\u00ecnh v\u1ec1 d\u1ea1ng $\\left[f(x)\\right]^2 + k > 0$ (v\u1edbi $k > 0$)<\/span> <br\/><span class='basic_left'><span class='basic_green'>B\u00e0i gi\u1ea3i:<\/span><br\/>Ta c\u00f3: $x^2 - 12x + 36 = (x - 6)^2$<br\/>V\u00ec $(x - 6)^2 \\geq 0$ v\u1edbi m\u1ecdi $x$ <br\/>V\u1eady $x^2 -12x + 36 < 0$ v\u00f4 nghi\u1ec7m<br\/>Ta ch\u1ecdn \u0111\u00e1p \u00e1n: <span class='basic_pink'>B. Sai<\/span><\/span> <br\/><\/span><br\/>","column":2}]}],"id_ques":1134},{"time":24,"part":[{"title":"L\u1ef1a ch\u1ecdn \u0111\u00e1p \u00e1n \u0111\u00fang nh\u1ea5t","title_trans":"","temp":"multiple_choice","correct":[[2]],"list":[{"point":5,"ques":"<span class='basic_left'><center><img src='https://www.luyenthi123.com/file/luyenthi123/lop8/toan/daiso/bai26/lv2/img\/5.jpg' \/><\/center> B\u1ea5t ph\u01b0\u01a1ng tr\u00ecnh $2x - 8 > x + 6$ t\u01b0\u01a1ng \u0111\u01b0\u01a1ng v\u1edbi b\u1ea5t ph\u01b0\u01a1ng tr\u00ecnh n\u00e0o trong c\u00e1c b\u1ea5t ph\u01b0\u01a1ng tr\u00ecnh sau?<\/span>","select":[" A. $x + 14 > 0$"," B. $x - 12 > 2$","C. $x + 8 > 6$","D. $x - 3 > 10$"],"hint":"","explain":"<span class='basic_left'><span class='basic_green'>H\u01b0\u1edbng d\u1eabn:<\/span><br\/>Hai b\u1ea5t ph\u01b0\u01a1ng tr\u00ecnh g\u1ecdi l\u00e0 t\u01b0\u01a1ng \u0111\u01b0\u01a1ng n\u1ebfu ch\u00fang c\u00f3 c\u00f9ng t\u1eadp nghi\u1ec7m<\/span> <br\/><span class='basic_left'><span class='basic_green'>B\u00e0i gi\u1ea3i:<\/span><br\/> Ta c\u00f3: <br\/>+ $2x - 8 > x + 6 \\Leftrightarrow 2x - x > 6 + 8 \\Leftrightarrow x > 14$ <br\/>V\u1eady nghi\u1ec7m c\u1ee7a b\u1ea5t ph\u01b0\u01a1ng tr\u00ecnh l\u00e0 $x > 14$ <b>(1)<\/b><br\/>+ $x + 14 > 0 \\Leftrightarrow x > -14$<br\/>V\u1eady nghi\u1ec7m c\u1ee7a b\u1ea5t ph\u01b0\u01a1ng tr\u00ecnh l\u00e0 $x > -14$ <br\/> <br\/>+ $x -12 > 2 \\Leftrightarrow x > 2 + 12 \\Leftrightarrow x > 14$<br\/>V\u1eady nghi\u1ec7m c\u1ee7a b\u1ea5t ph\u01b0\u01a1ng tr\u00ecnh l\u00e0 $x > 14$ <b>(2)<\/b><br\/>+ $x + 8 > 6 \\Leftrightarrow x > 6 - 8 \\Leftrightarrow x > -2$ <br\/>V\u1eady nghi\u1ec7m c\u1ee7a b\u1ea5t ph\u01b0\u01a1ng tr\u00ecnh l\u00e0 $x > -2$ <br\/>+ $x -3 > 10 \\Leftrightarrow x > 10 + 3 \\Leftrightarrow x > 13$ <br\/>V\u1eady nghi\u1ec7m c\u1ee7a b\u1ea5t ph\u01b0\u01a1ng tr\u00ecnh l\u00e0 $x > 13$<br\/>T\u1eeb (1) v\u00e0 (2) suy ra b\u1ea5t ph\u01b0\u01a1ng tr\u00ecnh $2x - 8 > x + 6$ t\u01b0\u01a1ng \u0111\u01b0\u01a1ng v\u1edbi b\u1ea5t ph\u01b0\u01a1ng tr\u00ecnh $x - 12 > 2$<br\/>V\u1eady ta ch\u1ecdn \u0111\u00e1p \u00e1n \u0111\u00fang l\u00e0 <span class='basic_pink'>B. $x - 12 > 2$<\/span><br\/>","column":2}]}],"id_ques":1135},{"time":24,"part":[{"title":"L\u1ef1a ch\u1ecdn \u0111\u00e1p \u00e1n \u0111\u00fang nh\u1ea5t","title_trans":"","temp":"multiple_choice","correct":[[3]],"list":[{"point":5,"ques":"<span class='basic_left'><center><img src='https://www.luyenthi123.com/file/luyenthi123/lop8/toan/daiso/bai26/lv2/img\/5.jpg' \/><\/center> B\u1ea5t ph\u01b0\u01a1ng tr\u00ecnh $5x - 3 < 12 + 2x$ t\u01b0\u01a1ng \u0111\u01b0\u01a1ng v\u1edbi b\u1ea5t ph\u01b0\u01a1ng tr\u00ecnh n\u00e0o trong c\u00e1c b\u1ea5t ph\u01b0\u01a1ng tr\u00ecnh sau?<\/span>","select":[" A. $x - 5 > 0$"," B. $x + 3 < -2$","C. $x - 2 < 3$","D. $2x - 6 < -16$"],"hint":"","explain":"<span class='basic_left'><span class='basic_green'>H\u01b0\u1edbng d\u1eabn:<\/span><br\/>Hai b\u1ea5t ph\u01b0\u01a1ng tr\u00ecnh g\u1ecdi l\u00e0 t\u01b0\u01a1ng \u0111\u01b0\u01a1ng n\u1ebfu ch\u00fang c\u00f3 c\u00f9ng t\u1eadp nghi\u1ec7m<\/span> <br\/><span class='basic_left'><span class='basic_green'>B\u00e0i gi\u1ea3i:<\/span><br\/> Ta c\u00f3: <br\/>+ $5x - 3 < 12 + 2x \\Leftrightarrow 5x - 2x < 12 + 3 \\Leftrightarrow 3x < 15 \\Leftrightarrow x < 5$ <br\/>V\u1eady nghi\u1ec7m c\u1ee7a b\u1ea5t ph\u01b0\u01a1ng tr\u00ecnh l\u00e0 $x < 5$ <b>(1)<\/b><br\/>+ $x - 5 > 0 \\Leftrightarrow x > 5$<br\/>V\u1eady nghi\u1ec7m c\u1ee7a b\u1ea5t ph\u01b0\u01a1ng tr\u00ecnh l\u00e0 $x > 5$ <br\/>+ $x + 3 < -2 \\Leftrightarrow x < -2 - 3 \\Leftrightarrow x < -5$<br\/>V\u1eady nghi\u1ec7m c\u1ee7a b\u1ea5t ph\u01b0\u01a1ng tr\u00ecnh l\u00e0 $x < -5$ <br\/>+ $x - 2 < 3 \\Leftrightarrow x < 3 + 2 \\Leftrightarrow x < 5$ <br\/>V\u1eady nghi\u1ec7m c\u1ee7a b\u1ea5t ph\u01b0\u01a1ng tr\u00ecnh l\u00e0 $x < 5$ <b>(2)<\/b><br\/>+ $2x - 6 < -16 \\Leftrightarrow 2x < -16 + 6 \\Leftrightarrow 2x < -10 \\Leftrightarrow x < -10 : 2 \\Leftrightarrow x < -5$<br\/> V\u1eady nghi\u1ec7m c\u1ee7a b\u1ea5t ph\u01b0\u01a1ng tr\u00ecnh l\u00e0 $x <-5$<br\/>T\u1eeb (1) v\u00e0 (2) suy ra b\u1ea5t ph\u01b0\u01a1ng tr\u00ecnh $5x - 3 < 12 + 2x$ t\u01b0\u01a1ng \u0111\u01b0\u01a1ng v\u1edbi b\u1ea5t ph\u01b0\u01a1ng tr\u00ecnh $x - 2 < 3$<br\/>V\u1eady ta ch\u1ecdn \u0111\u00e1p \u00e1n \u0111\u00fang l\u00e0 <span class='basic_pink'>C. $x - 2 < 3$<\/span><br\/>","column":2}]}],"id_ques":1136},{"time":24,"part":[{"title":"L\u1ef1a ch\u1ecdn \u0111\u00e1p \u00e1n \u0111\u00fang nh\u1ea5t","title_trans":"","temp":"multiple_choice","correct":[[1]],"list":[{"point":5,"ques":"<span class='basic_left'><center><img src='https://www.luyenthi123.com/file/luyenthi123/lop8/toan/daiso/bai26/lv2/img\/D8C4B2_TB101.png' \/><\/center> H\u00ecnh v\u1ebd tr\u00ean bi\u1ec3u di\u1ec5n t\u1eadp nghi\u1ec7m c\u1ee7a b\u1ea5t ph\u01b0\u01a1ng tr\u00ecnh n\u00e0o sau \u0111\u00e2y?<\/span>","select":[" A. $4x - 8 < 12 + 12x$"," B. $x - 3 > 7 - x$","C. $3x + 8 < 18 - x$","D. $x + 2 > -5$"],"hint":"","explain":"<span class='basic_left'>+ H\u00ecnh v\u1ebd tr\u00ean bi\u1ec3u di\u1ec5n t\u1eadp nghi\u1ec7m l\u00e0 $\\left\\{ x \\mid x > \\dfrac{-5}{2}\\right\\}$<br\/>+ $4x - 8 < 12 + 12x \\Leftrightarrow 12x - 4x > -8 - 12 \\Leftrightarrow 8x > -20 \\Leftrightarrow x > -20 : 8 \\Leftrightarrow x > \\dfrac{-5}{2}$<br\/> $\\Rightarrow$ H\u00ecnh v\u1ebd tr\u00ean bi\u1ec3u di\u1ec5n t\u1eadp nghi\u1ec7m c\u1ee7a b\u1ea5t ph\u01b0\u01a1ng tr\u00ecnh $4x - 8 < 12 + 12x$<br\/>+ $x - 3 > 7 - x \\Leftrightarrow x + x > 7 + 3 \\Leftrightarrow 2x > 10 \\Leftrightarrow x > 10 : 2 \\Leftrightarrow x > 5$<br\/>$\\Rightarrow$ H\u00ecnh v\u1ebd tr\u00ean kh\u00f4ng bi\u1ec3u di\u1ec5n t\u1eadp nghi\u1ec7m c\u1ee7a b\u1ea5t ph\u01b0\u01a1ng tr\u00ecnh $x - 3 > 7 - x$<br\/>+ $3x + 8 < 18 - x \\Leftrightarrow 3x + x < 18 - 8 \\Leftrightarrow 4x < 10 \\Leftrightarrow x < 10 : 4 \\Leftrightarrow x < \\dfrac{5}{2}$<br\/>$\\Rightarrow$ H\u00ecnh v\u1ebd tr\u00ean kh\u00f4ng bi\u1ec3u di\u1ec5n t\u1eadp nghi\u1ec7m c\u1ee7a b\u1ea5t ph\u01b0\u01a1ng tr\u00ecnh $3x + 8 < 18 - x$<br\/>+ $x + 2 > -5 \\Leftrightarrow x > -5 - 2 \\Leftrightarrow x > -7$<br\/>$\\Rightarrow$ H\u00ecnh v\u1ebd tr\u00ean kh\u00f4ng bi\u1ec3u di\u1ec5n t\u1eadp nghi\u1ec7m c\u1ee7a b\u1ea5t ph\u01b0\u01a1ng tr\u00ecnh $x + 2 > -5$<br\/>V\u1eady \u0111\u00e1p \u00e1n \u0111\u00fang l\u00e0 <span class='basic_pink'>A. $4x - 8 < 12 + 12x$<\/span><\/span>","column":2}]}],"id_ques":1137},{"time":24,"part":[{"title":"L\u1ef1a ch\u1ecdn \u0111\u00e1p \u00e1n \u0111\u00fang nh\u1ea5t","title_trans":"","temp":"multiple_choice","correct":[[1]],"list":[{"point":5,"ques":"<span class='basic_left'><center><img src='https://www.luyenthi123.com/file/luyenthi123/lop8/toan/daiso/bai26/lv2/img\/D8C4B2_TB103.png' \/><\/center> H\u00ecnh v\u1ebd tr\u00ean bi\u1ec3u di\u1ec5n t\u1eadp nghi\u1ec7m c\u1ee7a b\u1ea5t ph\u01b0\u01a1ng tr\u00ecnh n\u00e0o sau \u0111\u00e2y?<\/span>","select":[" A. $3x - 5 < 2x + 7$"," B. $x - 3 > 2 - x$","C. $2x - 6 > -30$","D. $x - 5 > 7 - 2x$"],"hint":"","explain":"<span class='basic_left'>+ H\u00ecnh v\u1ebd tr\u00ean bi\u1ec3u di\u1ec5n t\u1eadp nghi\u1ec7m l\u00e0 $\\left\\{ x \\mid x < 12 \\right\\}$<br\/>+ $3x - 5 < 2x + 7 \\Leftrightarrow 3x - 2x < 7 + 5 \\Leftrightarrow x < 12$<br\/> $\\Rightarrow$ H\u00ecnh v\u1ebd tr\u00ean bi\u1ec3u di\u1ec5n t\u1eadp nghi\u1ec7m c\u1ee7a b\u1ea5t ph\u01b0\u01a1ng tr\u00ecnh $3x - 5 < 2x + 7$<br\/>+ $x - 3 > 2 - x \\Leftrightarrow x + x > 2 + 3 \\Leftrightarrow 2x > 5 \\Leftrightarrow x > 5 : 2 \\Leftrightarrow x > 2,5$<br\/>$\\Rightarrow$ H\u00ecnh v\u1ebd tr\u00ean kh\u00f4ng bi\u1ec3u di\u1ec5n t\u1eadp nghi\u1ec7m c\u1ee7a b\u1ea5t ph\u01b0\u01a1ng tr\u00ecnh $x - 3 > 2 - x$<br\/>+ $2x - 6 > -30 \\Leftrightarrow 2x > -30 + 6 \\Leftrightarrow 2x > -24 \\Leftrightarrow x > -24 : 2 \\Leftrightarrow x > -12$<br\/>$\\Rightarrow$ H\u00ecnh v\u1ebd tr\u00ean kh\u00f4ng bi\u1ec3u di\u1ec5n t\u1eadp nghi\u1ec7m c\u1ee7a b\u1ea5t ph\u01b0\u01a1ng tr\u00ecnh $2x - 6 > -30$<br\/>+ $x - 5 > 7 - 2x \\Leftrightarrow x + 2x > 7 + 5 \\Leftrightarrow 3x > 12 \\Leftrightarrow x > 12 : 3 \\Leftrightarrow x > 4$<br\/>$\\Rightarrow$ H\u00ecnh v\u1ebd tr\u00ean kh\u00f4ng bi\u1ec3u di\u1ec5n t\u1eadp nghi\u1ec7m c\u1ee7a b\u1ea5t ph\u01b0\u01a1ng tr\u00ecnh $x - 5 > 7 - 2x$<br\/>V\u1eady \u0111\u00e1p \u00e1n \u0111\u00fang l\u00e0 <span class='basic_pink'>A. $3x - 5 < 2x + 7$<\/span><\/span>","column":2}]}],"id_ques":1138},{"time":24,"part":[{"title":"L\u1ef1a ch\u1ecdn \u0111\u00e1p \u00e1n \u0111\u00fang nh\u1ea5t","title_trans":"","temp":"multiple_choice","correct":[[3]],"list":[{"point":5,"ques":"<center><img src='https://www.luyenthi123.com/file/luyenthi123/lop8/toan/daiso/bai26/lv2/img\/3.jpg' \/><\/center><br\/>Gi\u1ea3i b\u1ea5t ph\u01b0\u01a1ng tr\u00ecnh $5x - 8 \\geq x + 24$","select":[" A. $\\left\\{x \\mid x \\geq 4 \\right\\}$"," B. $\\left\\{x \\mid x \\geq -4 \\right\\}$","C. $\\left\\{x \\mid x \\geq 8 \\right\\}$","D. $\\left\\{x \\mid \\geq -8 \\right\\}$"],"hint":"S\u1eed d\u1ee5ng quy t\u1eafc chuy\u1ec3n v\u1ebf v\u00e0 quy t\u1eafc nh\u00e2n v\u1edbi m\u1ed9t s\u1ed1 \u0111\u1ec3 gi\u1ea3i b\u1ea5t ph\u01b0\u01a1ng tr\u00ecnh.","explain":"<span class='basic_left'>Ta c\u00f3 $5x - 8 \\geq x + 24$<br\/>$\\Leftrightarrow 5x - x \\geq 24 + 8$<br\/>$\\Leftrightarrow 4x \\geq 32$<br\/>$\\Leftrightarrow x \\geq 32 : 4$ <br\/>$\\Leftrightarrow x \\geq 8$<br\/>V\u1eady t\u1eadp nghi\u1ec7m c\u1ee7a b\u1ea5t ph\u01b0\u01a1ng tr\u00ecnh l\u00e0 $\\left\\{x \\mid x \\geq 8\\right\\}$ <br\/>\u0110\u00e1p \u00e1n \u0111\u00fang l\u00e0 <span class='basic_pink'>C. $\\left\\{x \\mid x \\geq 8 \\right\\}$<\/span><\/span>","column":2}]}],"id_ques":1139},{"time":24,"part":[{"title":"L\u1ef1a ch\u1ecdn \u0111\u00e1p \u00e1n \u0111\u00fang nh\u1ea5t","title_trans":"","temp":"multiple_choice","correct":[[4]],"list":[{"point":5,"ques":"<center><img src='https://www.luyenthi123.com/file/luyenthi123/lop8/toan/daiso/bai26/lv2/img\/3.jpg' \/><\/center><br\/>Gi\u1ea3i b\u1ea5t ph\u01b0\u01a1ng tr\u00ecnh $-x - 8 \\leq -3x + 20$","select":[" A. $\\left\\{x \\mid x \\leq 6 \\right\\}$"," B. $\\left\\{x \\mid x \\leq -6 \\right\\}$","C. $\\left\\{x \\mid x \\leq -14 \\right\\}$","D. $\\left\\{x \\mid \\leq 14 \\right\\}$"],"hint":"S\u1eed d\u1ee5ng quy t\u1eafc chuy\u1ec3n v\u1ebf v\u00e0 quy t\u1eafc nh\u00e2n v\u1edbi m\u1ed9t s\u1ed1 \u0111\u1ec3 gi\u1ea3i b\u1ea5t ph\u01b0\u01a1ng tr\u00ecnh.","explain":"<span class='basic_left'>Ta c\u00f3 $-x - 8 \\leq -3x + 20$<br\/>$\\Leftrightarrow -x + 3x \\leq 20 + 8$<br\/>$\\Leftrightarrow 2x \\leq 28$<br\/>$\\Leftrightarrow x \\leq 28 : 2$ <br\/>$\\Leftrightarrow x \\leq 14$<br\/>V\u1eady t\u1eadp nghi\u1ec7m c\u1ee7a b\u1ea5t ph\u01b0\u01a1ng tr\u00ecnh l\u00e0 $\\left\\{x \\mid x \\leq 14\\right\\}$ <br\/>\u0110\u00e1p \u00e1n \u0111\u00fang l\u00e0 <span class='basic_pink'>D. $\\left\\{x \\mid x \\leq 14 \\right\\}$<\/span><\/span>","column":2}]}],"id_ques":1140}],"lesson":{"save":0,"level":2}}