{"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":[[[">"],["-5"]]],"list":[{"point":5,"width":50,"content":"","type_input":"","ques":"Gi\u1ea3i b\u1ea5t ph\u01b0\u01a1ng tr\u00ecnh: $-3x < 15$<br\/><b>\u0110\u00e1p \u00e1n:<\/b> $x$ _input_ _input_","hint":"","explain":"<span class='basic_left'>Ta c\u00f3:<br\/>$-3x < 15$ <br\/> $\\Leftrightarrow x > 15 : (-3)$ <br\/>$\\Leftrightarrow x > -5$<br\/>V\u1eady t\u1eadp nghi\u1ec7m c\u1ee7a b\u1ea5t ph\u01b0\u01a1ng tr\u00ecnh l\u00e0 $\\left\\{x \\mid x > -5\\right\\}$<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'>\">\"; $-5$<\/span><\/span>"}]}],"id_ques":1201},{"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/bai28/lv1/img\/3.jpg' \/><\/center><br\/>Gi\u1ea3i b\u1ea5t ph\u01b0\u01a1ng tr\u00ecnh $5x - 7 < 8$","select":[" A. $\\left\\{x \\mid x > 3\\right\\}$"," B. $\\left\\{x \\mid x < 3\\right\\}$","C. $\\left\\{x \\mid x > \\dfrac{-1}{2} \\right\\}$","D. $\\left\\{x \\mid x < \\dfrac{-1}{2} \\right\\}$"],"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.","explain":"<span class='basic_left'>Ta c\u00f3 $5x - 7 < 8$<br\/>$\\Leftrightarrow 5x < 8 + 7$ <br\/>$\\Leftrightarrow 5x < 15$<br\/>$\\Leftrightarrow x < 15 : 5$ <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":1202},{"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/bai28/lv1/img\/5.jpg' \/><\/center><br\/>Gi\u1ea3i b\u1ea5t ph\u01b0\u01a1ng tr\u00ecnh $6x > 8x - 10$","select":[" A. $\\left\\{x \\mid x > 5\\right\\}$"," B. $\\left\\{x \\mid x < 5\\right\\}$","C. $\\left\\{x \\mid x > -5 \\right\\}$","D. $\\left\\{x \\mid x < -5 \\right\\}$"],"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 $6x > 8x - 10$<br\/>$\\Leftrightarrow 6x - 8x > -10$ <br\/>$\\Leftrightarrow -2x > -10$<br\/>$\\Leftrightarrow x < (-10) : (-2)$ <br\/>$\\Leftrightarrow x < 5$<br\/>V\u1eady t\u1eadp nghi\u1ec7m c\u1ee7a b\u1ea5t ph\u01b0\u01a1ng tr\u00ecnh l\u00e0 $\\left\\{x \\mid x < 5\\right\\}$ <br\/>\u0110\u00e1p \u00e1n \u0111\u00fang l\u00e0 <span class='basic_pink'>B. $\\left\\{x \\mid x < 5\\right\\}$<\/span><\/span>","column":2}]}],"id_ques":1203},{"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/bai28/lv1/img\/7.jpg' \/><\/center><br\/>Gi\u1ea3i b\u1ea5t ph\u01b0\u01a1ng tr\u00ecnh $\\dfrac{2}{5}x > -6$","select":[" A. $\\left\\{x \\mid x > 15\\right\\}$"," B. $\\left\\{x \\mid x < -15\\right\\}$","C. $\\left\\{x \\mid x < 15 \\right\\}$","D. $\\left\\{x \\mid x > -15 \\right\\}$"],"hint":"S\u1eed d\u1ee5ng 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 $\\dfrac{2}{5}x > -6$ $\\Leftrightarrow x > -6 : \\dfrac{2}{5}$ $\\Leftrightarrow x > -6 . \\dfrac{5}{2}$ $\\Leftrightarrow x > -15$<br\/>V\u1eady t\u1eadp nghi\u1ec7m c\u1ee7a b\u1ea5t ph\u01b0\u01a1ng tr\u00ecnh l\u00e0 $\\left\\{x \\mid x > -15\\right\\}$ <br\/>\u0110\u00e1p \u00e1n \u0111\u00fang l\u00e0 <span class='basic_pink'>D. $\\left\\{x \\mid x > -15\\right\\}$<\/span><\/span>","column":2}]}],"id_ques":1204},{"time":24,"part":[{"title":"Ch\u1ecdn <u>nh\u1eefng<\/u> \u0111\u00e1p \u00e1n \u0111\u00fang","title_trans":"Ch\u1ecdn \u0111\u01b0\u1ee3c nhi\u1ec1u \u0111\u00e1p \u00e1n","temp":"checkbox","correct":[["1","2"]],"list":[{"point":5,"img":"","ques":"<span class='basic_left'>Trong c\u00e1c b\u1ea5t ph\u01b0\u01a1ng tr\u00ecnh sau, h\u00e3y cho bi\u1ebft b\u1ea5t ph\u01b0\u01a1ng tr\u00ecnh n\u00e0o l\u00e0 b\u1ea5t ph\u01b0\u01a1ng tr\u00ecnh b\u1eadc nh\u1ea5t m\u1ed9t \u1ea9n.<br\/><b>H\u00e3y ch\u1ecdn nh\u1eefng \u0111\u00e1p \u00e1n \u0111\u00fang<\/b><\/span>","hint":"","column":2,"number_true":2,"select":["A. $x - 6 > 0$","B. $3x - 15 \\geq 0$","C. $0.x + 8 > 0$","D. $x^2 - 1 > 7$"],"explain":"<span class='basic_left'>B\u1ea5t ph\u01b0\u01a1ng tr\u00ecnh d\u1ea1ng $ax + b < 0$ (ho\u1eb7c $ax + b > 0; ax + b \\leq 0; ax + b \\geq 0$) trong \u0111\u00f3 $a$ v\u00e0 $b$ l\u00e0 hai s\u1ed1 \u0111\u00e3 cho, $a \\neq 0$, \u0111\u01b0\u1ee3c g\u1ecdi l\u00e0 b\u1ea5t ph\u01b0\u01a1ng tr\u00ecnh b\u1eadc nh\u1ea5t m\u1ed9t \u1ea9n.<br\/>Do \u0111\u00f3 c\u00e1c \u0111\u00e1p \u00e1n \u0111\u00fang l\u00e0 <span class='basic_pink'>A. $x - 6 > 0$; B. $3x - 15 \\geq 0$ <\/span><\/span> "}]}],"id_ques":1205},{"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'>H\u00e3y l\u1eadp b\u1ea5t ph\u01b0\u01a1ng tr\u00ecnh cho b\u00e0i to\u00e1n sau:<br\/>Qu\u00e3ng \u0111\u01b0\u1eddng t\u1eeb $A$ \u0111\u1ebfn $B$ d\u00e0i $40km$. M\u1ed9t \u00f4t\u00f4 \u0111i t\u1eeb $A$ \u0111\u1ebfn $B$, kh\u1edfi h\u00e0nh l\u00fac $8$ gi\u1edd. H\u1ecfi \u00f4t\u00f4 ph\u1ea3i \u0111i v\u1edbi v\u1eadn t\u1ed1c bao nhi\u00eau ki-l\u00f4-m\u00e9t \u0111\u1ec3 \u0111\u1ebfn $B$ tr\u01b0\u1edbc $11$ gi\u1edd c\u00f9ng ng\u00e0y?<\/span>","select":[" A. $\\dfrac{40}{x} < 3$"," B. $\\dfrac{40}{x} > 3$","C. $\\dfrac{40}{x} < 8$","D. $\\dfrac{40}{x} > 10$"],"hint":"","explain":"<span class='basic_left'><span class='basic_green'>Ph\u01b0\u01a1ng ph\u00e1p gi\u1ea3i:<\/span><br\/> D\u1ef1a v\u00e0o d\u1eef ki\u1ec7n \u0111\u00e3 cho trong b\u00e0i to\u00e1n \u0111\u1ec3 ch\u1ecdn \u1ea9n s\u1ed1 $x$ r\u1ed3i d\u1ef1a v\u00e0o m\u1ed1i quan h\u1ec7 gi\u1eefa gi\u1ea3 thi\u1ebft c\u1ee7a b\u00e0i to\u00e1n v\u1edbi k\u1ebft lu\u1eadn c\u1ea7n t\u00ecm \u0111\u1ec3 l\u1eadp b\u1ea5t ph\u01b0\u01a1ng tr\u00ecnh.<\/span> <br\/><span class='basic_left'><span class='basic_green'>B\u00e0i gi\u1ea3i:<\/span><br\/> G\u1ecdi $x$ ($km\/h$) l\u00e0 v\u1eadn t\u1ed1c c\u1ee7a \u00f4t\u00f4 ($x > 0$)<br\/>Th\u1eddi gian \u00f4t\u00f4 \u0111i t\u1eeb $A$ \u0111\u1ebfn $B$ l\u00e0: $\\dfrac{40}{x}$ (gi\u1edd)<br\/>V\u00ec ph\u1ea3i \u0111\u1ebfn $B$ tr\u01b0\u1edbc $8$ gi\u1edd n\u00ean th\u1eddi gian \u00f4 t\u00f4 \u0111i t\u1eeb $A$ \u0111\u1ebfn $B$ ph\u1ea3i nh\u1ecf h\u01a1n $3$ gi\u1edd. Ta c\u00f3 b\u1ea5t ph\u01b0\u01a1ng tr\u00ecnh: $\\dfrac{40}{x} < 3$<br\/>V\u1eady \u0111\u00e1p \u00e1n \u0111\u00fang l\u00e0 <span class='basic_pink'>A. $\\dfrac{40}{x} < 3$<\/span>","column":2}]}],"id_ques":1206},{"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'>Ki\u1ec3m tra xem gi\u00e1 tr\u1ecb $x = 2$ l\u00e0 nghi\u1ec7m c\u1ee7a b\u1ea5t ph\u01b0\u01a1ng tr\u00ecnh n\u00e0o trong c\u00e1c b\u1ea5t ph\u01b0\u01a1ng tr\u00ecnh sau:<\/span>","select":[" A. $2x + 6 < 8$"," B. $3x + 5 > 12$","C. $4x - 5 > 2$","D. $x + 7 > 10$"],"hint":"","explain":"<span class='basic_left'><span class='basic_green'>Ph\u01b0\u01a1ng ph\u00e1p gi\u1ea3i:<\/span><br\/> Thay $x = a$ v\u00e0o hai v\u1ebf c\u1ee7a b\u1ea5t ph\u01b0\u01a1ng tr\u00ecnh:<br\/>+ N\u1ebfu \u0111\u01b0\u1ee3c b\u1ea5t \u0111\u1eb3ng th\u1ee9c \u0111\u00fang th\u00ec $x = a$ l\u00e0 nghi\u1ec7m<br\/>+ N\u1ebfu kh\u00f4ng \u0111\u01b0\u1ee3c b\u1ea5t \u0111\u1eb3ng th\u1ee9c \u0111\u00fang th\u00ec $x = a$ kh\u00f4ng l\u00e0 nghi\u1ec7m. <\/span> <br\/><span class='basic_left'><span class='basic_green'>B\u00e0i gi\u1ea3i:<\/span><br\/> + Thay $x = 2$ v\u00e0o b\u1ea5t ph\u01b0\u01a1ng tr\u00ecnh $2x + 6 < 8$, ta \u0111\u01b0\u1ee3c:<br\/>$VT = 2.2 + 6 = 10$; $VP = 8$<br\/>L\u1ea1i c\u00f3: $10 > 8$ n\u00ean $x = 2$ kh\u00f4ng l\u00e0 nghi\u1ec7m c\u1ee7a b\u1ea5t ph\u01b0\u01a1ng tr\u00ecnh<br\/>+ Thay $x = 2$ v\u00e0o b\u1ea5t ph\u01b0\u01a1ng tr\u00ecnh $3x + 5 > 12$, ta \u0111\u01b0\u1ee3c:<br\/>$VT = 3.2 + 5 = 11$; $VP = 12$<br\/>L\u1ea1i c\u00f3: $11 < 12$ n\u00ean $x = 2$ kh\u00f4ng l\u00e0 nghi\u1ec7m c\u1ee7a b\u1ea5t ph\u01b0\u01a1ng tr\u00ecnh<br\/>+ Thay $x = 2$ v\u00e0o b\u1ea5t ph\u01b0\u01a1ng tr\u00ecnh $4x - 5 > 2$, ta \u0111\u01b0\u1ee3c:<br\/>$VT = 4.2 - 5 = 3$; $VP = 2$<br\/>L\u1ea1i c\u00f3: $3 > 2$ n\u00ean $x = 2$ l\u00e0 nghi\u1ec7m c\u1ee7a b\u1ea5t ph\u01b0\u01a1ng tr\u00ecnh<br\/>+ Thay $x = 2$ v\u00e0o b\u1ea5t ph\u01b0\u01a1ng tr\u00ecnh $x + 7 > 10$, ta \u0111\u01b0\u1ee3c:<br\/>$VT = 2 + 7 = 9$; $VP = 10$<br\/>L\u1ea1i c\u00f3: $9 < 10$ n\u00ean $x = 2$ kh\u00f4ng l\u00e0 nghi\u1ec7m c\u1ee7a b\u1ea5t ph\u01b0\u01a1ng tr\u00ecnh<br\/>V\u1eady \u0111\u00e1p \u00e1n \u0111\u00fang l\u00e0 <span class='basic_pink'>C. $4x - 5 > 2$<\/span>","column":2}]}],"id_ques":1207},{"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'>B\u1ea5t ph\u01b0\u01a1ng tr\u00ecnh $x + 5 > 9$ v\u00e0 $2x - 3 > 5$ l\u00e0 hai b\u1ea5t ph\u01b0\u01a1ng tr\u00ecnh t\u01b0\u01a1ng \u0111\u01b0\u01a1ng. <b>\u0110\u00fang<\/b> hay <b> Sai<\/b>?<\/span>","select":[" A. \u0110\u00fang"," B. Sai"],"hint":"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.","explain":"<span class='basic_left'>Ta c\u00f3: <br\/>+) $x + 5 > 9 \\Leftrightarrow x > 9 - 5 \\Leftrightarrow x > 4$<br\/>+) $2x - 3 > 5 \\Leftrightarrow 2x > 5 + 3 \\Leftrightarrow 2x > 8 \\Leftrightarrow x > 8 : 2 \\Leftrightarrow x > 4$ <br\/>V\u1eady $x + 5 > 9 \\Leftrightarrow 2x - 3 > 5$ v\u00ec hai b\u1ea5t ph\u01b0\u01a1ng tr\u00ecnh c\u00f3 c\u00f9ng t\u1eadp nghi\u1ec7m $\\left\\{x \\mid x > 4\\right\\}$<br\/>Ta ch\u1ecdn \u0111\u00e1p \u00e1n <span class='basic_pink'>A. \u0110\u00fang<\/span><\/span>","column":2}]}],"id_ques":1208},{"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'>B\u1ea5t ph\u01b0\u01a1ng tr\u00ecnh $2x - 3 > 7$ v\u00e0 $x - 2 > 3$ l\u00e0 hai b\u1ea5t ph\u01b0\u01a1ng tr\u00ecnh t\u01b0\u01a1ng \u0111\u01b0\u01a1ng. <b>\u0110\u00fang<\/b> hay <b> Sai<\/b>?<\/span>","select":[" A. \u0110\u00fang"," B. Sai"],"hint":"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.","explain":"<span class='basic_left'>Ta c\u00f3: <br\/>+) $2x - 3 > 7 \\Leftrightarrow 2x > 7 + 3 \\Leftrightarrow 2x > 10 \\Leftrightarrow x > 10 : 2 \\Leftrightarrow x > 5$<br\/>+) $x - 2 > 3 \\Leftrightarrow x > 3 + 2 \\Leftrightarrow x > 5$ <br\/>V\u1eady $2x - 3 > 7 \\Leftrightarrow x - 2 > 3$ v\u00ec hai b\u1ea5t ph\u01b0\u01a1ng tr\u00ecnh c\u00f3 c\u00f9ng t\u1eadp nghi\u1ec7m $\\left\\{x \\mid x > 5\\right\\}$<br\/>Ta ch\u1ecdn \u0111\u00e1p \u00e1n <span class='basic_pink'>A. \u0110\u00fang<\/span><\/span>","column":2}]}],"id_ques":1209},{"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/bai28/lv1/img\/4.jpg' \/><\/center><br\/>Gi\u1ea3i ph\u01b0\u01a1ng tr\u00ecnh: $3|x| - 4 = 8$","select":[" A. $x = \\dfrac{4}{3}$ "," B. $x = \\dfrac{4}{3}$ ho\u1eb7c $x = -\\dfrac{4}{3}$","C. $x = 4$ ho\u1eb7c $x = -4$","D. $x = 4$ "],"hint":"","explain":"<span class='basic_left'>Ta c\u00f3:<br\/>$3|x| - 4 = 8$<br\/>$\\Leftrightarrow 3|x| = 8 + 4$<br\/>$\\Leftrightarrow 3|x| = 12$<br\/>$\\Leftrightarrow |x| = 12 : 3$<br\/>$\\Leftrightarrow |x| = 4$<br\/>$\\Rightarrow x = 4$ ho\u1eb7c $x = -4$<br\/>V\u1eady \u0111\u00e1p \u00e1n \u0111\u00fang l\u00e0 <span class='basic_pink'>C. $x = 4$ ho\u1eb7c $x = -4$<\/span><\/span><\/span>","column":2}]}],"id_ques":1210},{"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":"<center><img src='https://www.luyenthi123.com/file/luyenthi123/lop8/toan/daiso/bai28/lv1/img\/4.jpg' \/><\/center><br\/>Gi\u1ea3i ph\u01b0\u01a1ng tr\u00ecnh: $|x - 5| = 8$","select":[" A. $x = 13$ ho\u1eb7c $x = -3$ "," B. $x = -13$ ho\u1eb7c $x = 3$","C. $x = 13$ ho\u1eb7c $x = 3$","D. $x = -13$ ho\u1eb7c $x = -3$ "],"hint":"","explain":"<span class='basic_left'>Ta c\u00f3:<br\/>$|x - 5| = 8$<br\/>$\\Rightarrow$ $\\left[\\begin{array}{l} x - 5 = 8\\\\ x - 5 = -8\\end{array} \\right.$<br\/>$\\Leftrightarrow$ $\\left[\\begin{array}{l} x = 8 + 5\\\\ x = -8 + 5 \\end{array} \\right.$<br\/>$\\Leftrightarrow$ $\\left[\\begin{array}{l} x = 13\\\\ x = -3 \\end{array} \\right.$<br\/>V\u1eady \u0111\u00e1p \u00e1n \u0111\u00fang l\u00e0 <span class='basic_pink'> A. $x = 13$ ho\u1eb7c $x = -3$<\/span><\/span><\/span>","column":2}]}],"id_ques":1211},{"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/bai28/lv1/img\/7.jpg' \/><\/center><br\/>B\u1ecf d\u1ea5u gi\u00e1 tr\u1ecb tuy\u1ec7t \u0111\u1ed1i v\u00e0 r\u00fat g\u1ecdn bi\u1ec3u th\u1ee9c: $A = 3x + 5 - |8x|$ v\u1edbi $x \\geq 0$","select":[" $A = 13x - 5$ "," $A = 5x + 5$","$A = 13x + 5$","$A = -5x + 5$ "],"hint":"\u00c1p d\u1ee5ng \u0111\u1ecbnh ngh\u0129a gi\u00e1 tr\u1ecb tuy\u1ec7t \u0111\u1ed1i \u0111\u1ec3 r\u00fat g\u1ecdn: <br\/> $|x| = \\left\\{\\begin{array}{l} x \\hspace{0,2cm}\\text{n\u1ebfu } x \\geq 0\\\\-x \\hspace{0,2cm}\\text{n\u1ebfu x} < 0 \\end{array} \\right.$","explain":"<span class='basic_left'>Khi $x \\geq 0$, ta c\u00f3 $8x \\geq 0$ n\u00ean $|8x| = 8x$<br\/>V\u1eady<br\/>$A = 3x + 5 - |8x| = 3x + 5 - 8x = -5x + 5$<br\/>\u0110\u00e1p \u00e1n \u0111\u00fang l\u00e0 <span class='basic_pink'> $A = -5x + 5$<\/span><\/span>","column":2}]}],"id_ques":1212},{"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":"<center><img src='https://www.luyenthi123.com/file/luyenthi123/lop8/toan/daiso/bai28/lv1/img\/5.jpg' \/><\/center><br\/>B\u1ecf d\u1ea5u gi\u00e1 tr\u1ecb tuy\u1ec7t \u0111\u1ed1i v\u00e0 r\u00fat g\u1ecdn bi\u1ec3u th\u1ee9c: $C = |x - 2| + 3x$ v\u1edbi $x < 0$","select":[" $C = 2x + 2$ "," $C = 2x - 2$","$C = -2x - 2$","$C = 3x + 2$ "],"hint":"\u00c1p d\u1ee5ng \u0111\u1ecbnh ngh\u0129a gi\u00e1 tr\u1ecb tuy\u1ec7t \u0111\u1ed1i \u0111\u1ec3 r\u00fat g\u1ecdn: <br\/> $|x| = \\left\\{\\begin{array}{l} x \\hspace{0,2cm}\\text{n\u1ebfu x} \\geq 0\\\\-x \\hspace{0,2cm}\\text{n\u1ebfu } x < 0 \\end{array} \\right.$","explain":"<span class='basic_left'>Khi $x < 0$, ta c\u00f3 $x - 2 < 0$ n\u00ean $|x - 2| = -(x - 2) = -x + 2$<br\/>V\u1eady<br\/>$C = |x - 2| + 3x = -x + 2 + 3x = 2x + 2$<br\/>\u0110\u00e1p \u00e1n \u0111\u00fang l\u00e0 <span class='basic_pink'>$C = 2x + 2$<\/span><\/span>","column":2}]}],"id_ques":1213},{"time":24,"part":[{"title":"\u0110i\u1ec1n \u0111\u00e1p \u00e1n th\u00edch h\u1ee3p v\u00e0o ch\u1ed7 tr\u1ed1ng","title_trans":"","temp":"fill_the_blank","correct":[[["8x"]]],"list":[{"point":5,"width":50,"content":"","type_input":"","ques":"N\u1ebfu $x > 0$ th\u00ec $|-8x| =$ <span class='basic_hoi_black'>?<\/span><br\/><b>\u0110\u00e1p \u00e1n:<\/b> $|-8x| = $ _input_ ","hint":"","explain":"<span class='basic_left'>Khi $x > 0$, ta c\u00f3 $-8x < 0$ n\u00ean $|-8x| = -(8x) = 8x $<br\/>V\u1eady \u0111\u00e1p \u00e1n c\u1ea7n \u0111i\u1ec1n v\u00e0o \u00f4 tr\u1ed1ng l\u00e0 <span class='basic_pink'>8x<\/span><\/span>"}]}],"id_ques":1214},{"time":24,"part":[{"title":"Ch\u1ecdn \u0111\u00e1p \u00e1n \u0111\u00fang","title_trans":"","temp":"multiple_choice","correct":[[[1]]],"list":[{"point":5,"ques":"N\u1ebfu $x > 0$ th\u00ec $|x + 8| =$ <span class='basic_hoi_black'>?<\/span><br\/>","select":["A. $x + 8$","B. $-(x+8)$"],"hint":"","explain":"<span class='basic_left'>Khi $x > 0$, ta c\u00f3 $x + 8 > 0$ n\u00ean $|x + 8| = x + 8$<\/span>"}]}],"id_ques":1215},{"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":"<center><img src='https://www.luyenthi123.com/file/luyenthi123/lop8/toan/daiso/bai28/lv1/img\/8.jpg' \/><\/center><br\/> N\u1ebfu $x < 0$ th\u00ec $|x - 5| = 5 - x$. <b>\u0110\u00fang<\/b> hay <b> Sai<\/b>?","select":[" A. \u0110\u00fang"," B. Sai "],"hint":"\u00c1p d\u1ee5ng \u0111\u1ecbnh ngh\u0129a gi\u00e1 tr\u1ecb tuy\u1ec7t \u0111\u1ed1i: <br\/>$|x| = \\left\\{\\begin{array}{l} x \\hspace{0,2cm}\\text{n\u1ebfu}\\hspace{0,2cm} x \\geq 0\\\\ -x \\hspace{0,2cm}\\text{n\u1ebfu}\\hspace{0,2cm} x < 0\\end{array} \\right.$","explain":"<span class='basic_left'>Khi $x < 0$, ta c\u00f3 $x - 5 < 0$ n\u00ean $|x - 5| = -(x - 5) = 5 - x$<br\/>V\u1eady ta ch\u1ecdn \u0111\u00e1p \u00e1n <span class='basic_pink'>A. \u0110\u00fang<\/span> ","column":2}]}],"id_ques":1216},{"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":"Gi\u1ea3i ph\u01b0\u01a1ng tr\u00ecnh: $|x + 4| = |7|$","select":[" $S = \\left\\{-11 ; -3\\right\\}$"," $S = \\left\\{-11 ; 3\\right\\}$ ","$S = \\left\\{11 ; 3\\right\\}$","$S = \\left\\{-3 ; 11\\right\\}$"],"hint":"\u00c1p d\u1ee5ng \u0111\u1ecbnh ngh\u0129a gi\u00e1 tr\u1ecb tuy\u1ec7t \u0111\u1ed1i: <br\/>$|x| = \\left\\{\\begin{array}{l} x \\hspace{0,2cm}\\text{n\u1ebfu}\\hspace{0,2cm} x \\ge 0\\\\ -x \\hspace{0,2cm}\\text{n\u1ebfu}\\hspace{0,2cm} x < 0\\end{array} \\right.$","explain":"<span class='basic_left'>Ta c\u00f3:<br\/>$|x + 4| = |7|$ <br\/>$\\Leftrightarrow |x + 4| = 7$<br\/>$\\Leftrightarrow \\left\\{\\begin{array}{l} x + 4 = 7\\\\ x + 4 = -7\\end{array} \\right.$<br\/>$\\Leftrightarrow \\left\\{\\begin{array}{l} x = 3\\\\ x = -11\\end{array} \\right.$<br\/>V\u1eady $S = \\left\\{-11 ; 3\\right\\}$<br\/><span class='basic_pink'>\u0110\u00e1p \u00e1n \u0111\u00fang l\u00e0 $S = \\left\\{-11 ; 3\\right\\}$ <\/span><br\/> ","column":2}]}],"id_ques":1217},{"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":"Gi\u1ea3i ph\u01b0\u01a1ng tr\u00ecnh: $|x + 2| = |3 - 2x|$<br\/><b>T\u1eadp nghi\u1ec7m c\u1ee7a ph\u01b0\u01a1ng tr\u00ecnh l\u00e0:<\/b>","select":[" A. $S = \\left\\{-1 ; 5\\right\\}$"," B. $S = \\left\\{1 ; 5\\right\\}$ ","C. $S = \\left\\{\\dfrac{-1}{3} ; 5\\right\\}$","D. $S = \\left\\{\\dfrac{1}{3} ; 5\\right\\}$"],"hint":"$|A(x)| = |B(x)| \\Leftrightarrow A(x) = \\pm B(x)$ ","explain":"<span class='basic_left'>Ta c\u00f3:<br\/>$|x + 2| = |3 - 2x|$ <br\/>$\\Leftrightarrow \\left[\\begin{array}{l} x + 2 = 3 - 2x\\\\ x + 2 = -(3- 2x)\\end{array} \\right.$<br\/>$\\Leftrightarrow \\left[\\begin{array}{l} x + 2x = 3 - 2\\\\ x + 2 = -3 + 2x\\end{array} \\right.$<br\/>$\\Leftrightarrow \\left[\\begin{array}{l} 3x = 1\\\\ 2x - x = 2 + 3\\end{array} \\right.$<br\/>$\\Leftrightarrow \\left[\\begin{array}{l} x = \\dfrac{1}{3} \\\\ x = 5\\end{array} \\right.$<br\/>V\u1eady t\u1eadp nghi\u1ec7m c\u1ee7a ph\u01b0\u01a1ng tr\u00ecnh l\u00e0 $S = \\left\\{\\dfrac{1}{3} ; 5\\right\\}$<br\/><span class='basic_pink'>\u0110\u00e1p \u00e1n \u0111\u00fang l\u00e0 D <\/span><br\/> ","column":2}]}],"id_ques":1218},{"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":"Gi\u1ea3i ph\u01b0\u01a1ng tr\u00ecnh: $|2x + 1| = |5 - 3x|$<br\/><b>T\u1eadp nghi\u1ec7m c\u1ee7a ph\u01b0\u01a1ng tr\u00ecnh l\u00e0:<\/b>","select":[" A. $S = \\left\\{-1 ; 6\\right\\}$"," B. $S = \\left\\{1 ; -6\\right\\}$ ","C. $S = \\left\\{\\dfrac{4}{5} ; 6\\right\\}$","D. $S = \\left\\{\\dfrac{-4}{5} ; -6\\right\\}$"],"hint":"$|A(x)| = |B(x)| \\Leftrightarrow A(x) = \\pm B(x)$ ","explain":"<span class='basic_left'>Ta c\u00f3:<br\/>$|2x + 1| = |5 - 3x|$ <br\/>$\\Leftrightarrow \\left[\\begin{array}{l} 2x + 1 = 5 - 3x\\\\ 2x + 1 = -(5- 3x)\\end{array} \\right.$<br\/>$\\Leftrightarrow \\left[\\begin{array}{l} 2x + 3x = 5 - 1\\\\ 2x + 1 = -5 + 3x\\end{array} \\right.$<br\/>$\\Leftrightarrow \\left[\\begin{array}{l} 5x = 4\\\\ 3x - 2x =1 + 5\\end{array} \\right.$<br\/>$\\Leftrightarrow \\left[\\begin{array}{l} x = \\dfrac{4}{5} \\\\ x = 6\\end{array} \\right.$<br\/>V\u1eady t\u1eadp nghi\u1ec7m c\u1ee7a ph\u01b0\u01a1ng tr\u00ecnh l\u00e0 $S = \\left\\{\\dfrac{4}{5} ; 6\\right\\}$<br\/><span class='basic_pink'>\u0110\u00e1p \u00e1n \u0111\u00fang l\u00e0 C <\/span><br\/> ","column":2}]}],"id_ques":1219},{"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":"<center><img src='https://www.luyenthi123.com/file/luyenthi123/lop8/toan/daiso/bai28/lv1/img\/4.jpg' \/><\/center><br\/>Gi\u1ea3i ph\u01b0\u01a1ng tr\u00ecnh: $|x + 3| = 12$<br\/><b>Nghi\u1ec7m c\u1ee7a ph\u01b0\u01a1ng tr\u00ecnh l\u00e0:<\/b>","select":[" A. $x = 9$ ho\u1eb7c $x = -15$ "," B. $x = -9$ ho\u1eb7c $x = 15$","C. $x = 9$ ho\u1eb7c $x = 15$","D. $x = -9$ ho\u1eb7c $x = -15$ "],"hint":"","explain":"<span class='basic_left'>Ta c\u00f3:<br\/>$|x + 3| = 12$<br\/>$\\Rightarrow$ $\\left[\\begin{array}{l} x + 3 = 12\\\\ x + 3 = -12\\end{array} \\right.$<br\/>$\\Leftrightarrow$ $\\left[\\begin{array}{l} x = 12 - 3\\\\ x = -12 - 3 \\end{array} \\right.$<br\/>$\\Leftrightarrow$ $\\left[\\begin{array}{l} x = 9\\\\ x = -15 \\end{array} \\right.$<br\/>V\u1eady \u0111\u00e1p \u00e1n \u0111\u00fang l\u00e0 <span class='basic_pink'> A. $x = 9$ ho\u1eb7c $x = -15$<\/span><\/span><\/span>","column":2}]}],"id_ques":1220}],"lesson":{"save":0,"level":1}}