{"segment":[{"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/lop7/toan/daiso/bai11/lv1/img\/2.jpg' \/><\/center> T\u00ecm $x \\in \\mathbb{Q}$ bi\u1ebft $\\dfrac{-2}{3}x = \\left(\\dfrac{-1}{3}\\right)^{2} $ ","select":["A. $x = \\dfrac{1}{6} $ ","B. $x = \\dfrac{-2}{27} $ ","C. $x = \\dfrac{-1}{6} $","D. $x = \\dfrac{2}{27} $"],"hint":"L\u01b0u \u00fd: $(-a)^{n} = a^{n}$ n\u1ebfu n ch\u1eb5n ","explain":" Ta c\u00f3: $\\dfrac{-2}{3}x = \\left(\\dfrac{-1}{3}\\right)^{2} \\\\ \\Leftrightarrow \\dfrac{-2}{3}x = \\dfrac{1}{9} \\\\ \\Leftrightarrow x = \\dfrac{1}{9} : \\dfrac{-2}{3} \\\\ \\Leftrightarrow x = \\dfrac{-1}{6} $ <br\/> <br\/> <span class='basic_pink'> \u0110\u00e1p \u00e1n \u0111\u00fang l\u00e0 C. <\/span><\/span> ","column":2}]}],"id_ques":501},{"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\u00e1 tr\u1ecb bi\u1ec3u th\u1ee9c $P = \\dfrac{-5}{37} + \\dfrac{-4}{13} + \\dfrac{5}{37} + \\dfrac{-9}{13}$ l\u00e0: ","select":["A. $1$ ","B. $-1$ ","C. $0$","D. $2$ "],"hint":" Nh\u00f3m s\u1ed1 h\u1ea1ng m\u1ed9t c\u00e1ch h\u1ee3p l\u00ed r\u1ed3i th\u1ef1c hi\u1ec7n ph\u00e9p t\u00ednh.","explain":" Ta c\u00f3: $P = \\dfrac{-5}{37} + \\dfrac{-4}{13} + \\dfrac{5}{37} + \\dfrac{-9}{13} \\\\ = \\left(\\dfrac{-5}{37} + \\dfrac{5}{37} \\right) + \\left(\\dfrac{-4}{13} + \\dfrac{-9}{13}\\right) \\\\ = 0 + (-1) \\\\ = -1 $ <br\/> <br\/> <span class='basic_pink'> \u0110\u00e1p \u00e1n \u0111\u00fang l\u00e0 B. <\/span><\/span> ","column":4}]}],"id_ques":502},{"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":" Th\u1ef1c hi\u1ec7n ph\u00e9p t\u00ednh $Q = -3,94 . 0,5 . (-0,4) . 2,5 . (-2)$ b\u1eb1ng:","select":["A. $-3,94 $ ","B. $3,94$ ","C. $39,4$","D. $-39,4$ "],"hint":" Nh\u00f3m s\u1ed1 h\u1ea1ng m\u1ed9t c\u00e1ch h\u1ee3p l\u00ed r\u1ed3i th\u1ef1c hi\u1ec7n ph\u00e9p t\u00ednh.","explain":" Ta c\u00f3: $Q = -3,94 . 0,5 . (-0,4) . 2,5 . (-2) \\\\ = -3,94 . (-0,4 . 2,5) . (0,5 . (-2)) \\\\ = -3,94 . (-1) . (-1) \\\\ = -3,94 $ <br\/> <br\/> <span class='basic_pink'> \u0110\u00e1p \u00e1n \u0111\u00fang l\u00e0 A. <\/span><\/span> ","column":4}]}],"id_ques":503},{"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/lop7/toan/daiso/bai11/lv1/img\/6.jpg' \/><\/center> L\u00e0m tr\u00f2n s\u1ed1 2017,456 \u0111\u1ebfn ch\u1eef s\u1ed1 th\u1eadp ph\u00e2n th\u1ee9 nh\u1ea5t ta \u0111\u01b0\u1ee3c k\u1ebft qu\u1ea3 l\u00e0: ","select":["A. 2017,460 ","B. 2017,500","C. 2017,000","D. 2017,400"],"explain":" <span class='basic_left'><span class='basic_green'>H\u01b0\u1edbng d\u1eabn:<\/span><br\/><b> Quy \u01b0\u1edbc l\u00e0m tr\u00f2n s\u1ed1 <\/b> <br\/> * N\u1ebfu ch\u1eef s\u1ed1 \u0111\u1ea7u ti\u00ean trong c\u00e1c ch\u1eef s\u1ed1 b\u1ecb b\u1ecf \u0111i nh\u1ecf h\u01a1n 5 th\u00ec ta gi\u1eef nguy\u00ean b\u1ed9 ph\u1eadn c\u00f2n l\u1ea1i. Trong tr\u01b0\u1eddng h\u1ee3p s\u1ed1 nguy\u00ean th\u00ec ta thay c\u00e1c ch\u1eef s\u1ed1 b\u1ecf \u0111i b\u1eb1ng c\u00e1c ch\u1eef s\u1ed1 0. <br\/> * N\u1ebfu ch\u1eef s\u1ed1 \u0111\u1ea7u ti\u00ean trong c\u00e1c ch\u1eef s\u1ed1 b\u1ecb b\u1ecf \u0111i l\u1edbn h\u01a1n ho\u1eb7c b\u1eb1ng 5 th\u00ec c\u1ed9ng th\u00eam 1 v\u00e0o ch\u1eef s\u1ed1 cu\u1ed1i c\u00f9ng c\u1ee7a b\u1ed9 ph\u1eadn c\u00f2n l\u1ea1i. Trong tr\u01b0\u1eddng h\u1ee3p s\u1ed1 nguy\u00ean th\u00ec ta thay c\u00e1c ch\u1eef s\u1ed1 b\u1ecf \u0111i b\u1eb1ng c\u00e1c ch\u1eef s\u1ed1 0. <\/span> <br\/><br\/><span class='basic_green'>B\u00e0i gi\u1ea3i:<\/span><br\/> Ta nh\u1eadn th\u1ea5y s\u1ed1 2017,456 c\u00f3 ch\u1eef s\u1ed1 th\u1eadp ph\u00e2n th\u1ee9 nh\u1ea5t l\u00e0 4. <br\/> Ch\u1eef s\u1ed1 \u0111\u1ea7u ti\u00ean b\u1ecb b\u1ecf \u0111i l\u00e0 5 (b\u1eb1ng 5) n\u00ean ph\u1ea3i c\u1ed9ng th\u00eam 1 v\u00e0o 4. <br\/> L\u00e0m tr\u00f2n s\u1ed1 2017,456 \u0111\u1ebfn \u0111\u1ebfn ch\u1eef s\u1ed1 th\u1eadp ph\u00e2n th\u1ee9 nh\u1ea5t ta \u0111\u01b0\u1ee3c 2017,500. <br\/> <br\/> <span class='basic_pink'> \u0110\u00e1p \u00e1n \u0111\u00fang l\u00e0 B. <\/span><\/span>","column":2}]}],"id_ques":504},{"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/lop7/toan/daiso/bai11/lv1/img\/6.jpg' \/><\/center> T\u00ecm $x, y$ bi\u1ebft r\u1eb1ng $\\dfrac{x}{3} = \\dfrac{y}{5}$ v\u00e0 $x + y = 16 $ ","select":["A. $x = 8; y = 8$ ","B. $x = 7; y = 9$","C. $x = 6; y = 10$","D. $x = -6; y = -10 $"],"hint":"\u00c1p d\u1ee5ng t\u00ednh ch\u1ea5t d\u00e3y t\u1ec9 s\u1ed1 b\u1eb1ng nhau.","explain":" \u00c1p d\u1ee5ng t\u00ednh ch\u1ea5t d\u00e3y t\u1ec9 s\u1ed1 b\u1eb1ng nhau, ta c\u00f3: <br\/> $\\dfrac{x}{3} = \\dfrac{y}{5} = \\dfrac{x+y}{3+5} = \\dfrac{16}{8} = 2$ <br\/> Suy ra $ \\begin{cases} \\dfrac{x}{3} = 2 \\Rightarrow x = 3.2 = 6 \\\\ \\dfrac{y}{5} = 2 \\Rightarrow y = 5.2 = 10 \\end{cases} $ <br\/> V\u1eady gi\u00e1 tr\u1ecb c\u1ee7a $x; y$ l\u00e0: $x = 6; y = 10$ <br\/> <br\/> <span class='basic_pink'> \u0110\u00e1p \u00e1n \u0111\u00fang l\u00e0 C. <\/span><\/span> ","column":2}]}],"id_ques":505},{"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/lop7/toan/daiso/bai11/lv1/img\/6.jpg' \/><\/center> K\u1ebft qu\u1ea3 c\u1ee7a ph\u00e9p t\u00ednh $(-5)^{5}.(-5)^{7}$ l\u00e0: ","select":["A. $(-5)^{35}$ ","B. $5^{12}$","C. $(-5)^{2}$","D. $(-5)^{19}$"],"hint":"Xem l\u0169y th\u1eeba c\u1ee7a s\u1ed1 h\u1eefu t\u1ec9.","explain":" <span class='basic_left'><span class='basic_green'>H\u01b0\u1edbng d\u1eabn:<\/span> <br\/> \u00c1p d\u1ee5ng: $a^{m}.a^{n} = a^{m+n}$<\/span> <br\/> <br\/> <span class='basic_green'>B\u00e0i gi\u1ea3i:<\/span><br\/> Ta c\u00f3: $(-5)^{5}.(-5)^{7} = (-5)^{5+7} = (-5)^{12} = 5^{12} $ <br\/> <br\/> <span class='basic_pink'> \u0110\u00e1p \u00e1n \u0111\u00fang l\u00e0 B. <\/span><\/span> ","column":4}]}],"id_ques":506},{"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/lop7/toan/daiso/bai11/lv1/img\/4.jpg' \/><\/center> T\u00ecm $x$ bi\u1ebft r\u1eb1ng: <br\/> $\\dfrac{x}{3} = \\dfrac{y}{5} = \\dfrac{z}{-2}$ v\u00e0 $5x - y + 3z = -16 $ ","select":["A. $x = 8$ ","B. $x = -20$","C. $x = -12$","D. $x = -4 $"],"hint":"\u00c1p d\u1ee5ng t\u00ednh ch\u1ea5t d\u00e3y t\u1ec9 s\u1ed1 b\u1eb1ng nhau.","explain":" <span class='basic_left'> Ta c\u00f3: $\\dfrac{x}{3} = \\dfrac{y}{5} = \\dfrac{z}{-2}$ <br\/> Suy ra $\\dfrac{5x}{15} = \\dfrac{y}{5} = \\dfrac{-3z}{6}$ <br\/> \u00c1p d\u1ee5ng t\u00ednh ch\u1ea5t d\u00e3y t\u1ec9 s\u1ed1 b\u1eb1ng nhau, ta c\u00f3: <br\/> $\\dfrac{5x}{15} = \\dfrac{y}{5} = \\dfrac{3z}{-6} = \\dfrac{5x-y+3z}{15-5-6} = \\dfrac{-16}{4} = -4$ <br\/> Suy ra $ \\dfrac{x}{3} = -4 \\Rightarrow x = 3.(-4) = -12 $ <br\/> V\u1eady gi\u00e1 tr\u1ecb c\u1ee7a $x$ l\u00e0 $x = -12$ <br\/> <br\/> <span class='basic_pink'> \u0110\u00e1p \u00e1n \u0111\u00fang l\u00e0 C. <\/span><\/span> ","column":2}]}],"id_ques":507},{"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/lop7/toan/daiso/bai11/lv1/img\/4.jpg' \/><\/center> T\u00ecm $x$ bi\u1ebft r\u1eb1ng: <br\/> $[(-2017)^{7}]^{2} = (-2017)^{x} $ ","select":["A. $x = 5$ ","B. $x = 49$","C. $x = 9$","D. $x = 14 $"],"hint":"\u00c1p d\u1ee5ng t\u00ecm s\u1ed1 m\u0169 c\u1ee7a m\u1ed9t l\u0169y th\u1eeba.","explain":" <span class='basic_left'><span class='basic_green'>H\u01b0\u1edbng d\u1eabn:<\/span> <br\/> T\u00ecm s\u1ed1 m\u0169 c\u1ee7a m\u1ed9t l\u0169y th\u1eeba: <br\/> V\u1edbi $a \\neq 0; a \\neq \\pm 1,$ n\u1ebfu $a^{m} = a^{n}$ th\u00ec $m = n$<\/span> <br\/> <br\/> <span class='basic_green'>B\u00e0i gi\u1ea3i:<\/span><br\/> Ta c\u00f3: $[(-2017)^{7}]^{2} = (-2017)^{x} \\\\ \\Leftrightarrow (-2017)^{14} = (-2017)^{x} \\\\ \\Leftrightarrow x = 14 $ <br\/> <br\/> <span class='basic_pink'> \u0110\u00e1p \u00e1n \u0111\u00fang l\u00e0 D. <\/span><\/span> ","column":2}]}],"id_ques":508},{"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/lop7/toan/daiso/bai11/lv1/img\/4.jpg' \/><\/center> T\u00ecm $x$ bi\u1ebft r\u1eb1ng $ (2x - 1)^{3} = 27 $ ","select":["A. $x = 22$ ","B. $x = -12$","C. $x = 2$","D. $x = 3 $"],"hint":"\u0110\u01b0a v\u1ec1 hai l\u0169y th\u1eeba c\u00f9ng s\u1ed1 m\u0169 r\u1ed3i t\u00ecm $x$.","explain":" <span class='basic_left'><span class='basic_green'>H\u01b0\u1edbng d\u1eabn:<\/span> <br\/> T\u00ecm c\u01a1 s\u1ed1 c\u1ee7a m\u1ed9t l\u0169y th\u1eeba: <br\/> V\u1edbi $ n \\in \\mathbb{N}; n \\geq 1,$ n\u1ebfu $ a^{n} = b^{n}$ th\u00ec: <br\/> $ \\qquad a = b$ n\u1ebfu n l\u1ebb; <br\/> $\\qquad a = \\pm b$ n\u1ebfu n ch\u1eb5n. <\/span> <br\/> <br\/> <span class='basic_green'>B\u00e0i gi\u1ea3i:<\/span><br\/> Ta c\u00f3: $ (2x - 1)^{3} = 27 \\\\ \\Leftrightarrow (2x - 1)^{3} = 3^{3} \\\\ \\Leftrightarrow 2x - 1 = 3 \\\\ \\Leftrightarrow 2x = 1 + 3 = 4 \\\\ \\Leftrightarrow x = 4 : 2 \\\\ \\Leftrightarrow x = 2 $ <br\/> <br\/> <span class='basic_pink'> \u0110\u00e1p \u00e1n \u0111\u00fang l\u00e0 C. <\/span><\/span> ","column":2}]}],"id_ques":509},{"time":24,"part":[{"title":"L\u1ef1a ch\u1ecdn \u0111\u00fang hay sai","title_trans":"L\u1ef1a ch\u1ecdn \u0111\u00fang hay sai","temp":"true_false","correct":[["f","f","f","t"]],"list":[{"point":5,"image":"","col_name":["","\u0110\u00fang","Sai"],"arr_ques":["$\\sqrt{25} \\notin \\mathbb{N}$ "," $0 \\in \\mathbb{I}$ "," $1\\dfrac{3}{4} \\in \\mathbb{Z}$ ","$0,(13) \\notin \\mathbb{I}$"],"explain":[" V\u00ec $\\sqrt{25} = 5 \\in \\mathbb{N}$","<br\/> V\u00ec $0 \\in \\mathbb{Q}$ n\u00ean $0 \\notin \\mathbb{I}$","<br\/> V\u00ec $1\\dfrac{3}{4} = \\dfrac{7}{4} \\in \\mathbb {Q} \\notin \\mathbb{Z}$","<br\/> V\u00ec $0,(13) = \\dfrac{13}{10}\\in\\mathbb{Q} \\notin \\mathbb{I}$ "]}]}],"id_ques":510},{"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":" Trong c\u00e1c s\u1ed1 $\\sqrt{\\dfrac{4}{25}}; 0,(6); \\dfrac{-6}{10}; \\dfrac{-9}{-15},$ s\u1ed1 n\u00e0o bi\u1ec3u di\u1ec5n s\u1ed1 h\u1eefu t\u1ec9 $\\dfrac{3}{5}$? ","select":["A. $\\sqrt{\\dfrac{4}{25}}$ ","B. $0,(6)$","C. $ \\dfrac{-6}{10} $","D. $\\dfrac{-9}{-15} $"],"hint":"R\u00fat g\u1ecdn c\u00e1c s\u1ed1 \u0111\u00e3 cho v\u1ec1 ph\u00e2n s\u1ed1 t\u1ed1i gi\u1ea3n r\u1ed3i so s\u00e1nh v\u1edbi $\\dfrac{3}{5}$.","explain":" Ta c\u00f3: $\\sqrt{\\dfrac{4}{25}} = \\dfrac{2}{5} \\\\ 0,(6) = \\dfrac{6}{9} = \\dfrac{2}{3} \\\\ \\dfrac{-6}{10} = \\dfrac{-3}{5} \\\\ \\dfrac{-9}{-15} = \\dfrac{9}{15} = \\dfrac{3}{5}$ <br\/> V\u1eady s\u1ed1 bi\u1ec3u di\u1ec5n s\u1ed1 h\u1eefu t\u1ec9 $\\dfrac{3}{5}$ l\u00e0 $\\dfrac{-9}{-15}.$ <br\/> <br\/> <span class='basic_pink'> \u0110\u00e1p \u00e1n \u0111\u00fang l\u00e0 D. <\/span><\/span> ","column":2}]}],"id_ques":511},{"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/lop7/toan/daiso/bai11/lv1/img\/2.jpg' \/><\/center> T\u00ecm $x \\in \\mathbb{Q}$ bi\u1ebft: <br\/> $\\left| x + \\dfrac{1}{3}\\right| - 4 = -1 $ ","select":["A. $x = 2\\dfrac{2}{3} $ ho\u1eb7c $x = -3\\dfrac{1}{3}$ ","B. $x = \\dfrac{8}{3} $ ","C. $x = \\dfrac{3}{8} $","D. $x = \\varnothing $"],"explain":" <span class='basic_left'><span class='basic_green'>H\u01b0\u1edbng d\u1eabn:<\/span> <br\/> N\u1ebfu $|x| = a$ (v\u1edbi $a \\geq 0$) <br\/> th\u00ec $x = \\pm a $ <br\/> <span class='basic_green'>B\u00e0i gi\u1ea3i:<\/span><br\/> Ta c\u00f3: $\\left| x + \\dfrac{1}{3}\\right| - 4 = -1 \\\\ \\Rightarrow \\left| x + \\dfrac{1}{3}\\right| = 4 - 1 = 3 $ <br\/> $\\Rightarrow x + \\dfrac{1}{3} = \\pm 3$ <br\/> Tr\u01b0\u1eddng h\u1ee3p 1: $x + \\dfrac{1}{3} = 3 \\Rightarrow x = 3 - \\dfrac{1}{3} = \\dfrac{8}{3} = 2\\dfrac{2}{3}$ <br\/> Tr\u01b0\u1eddng h\u1ee3p 2: $ x + \\dfrac{1}{3} = -3 \\Rightarrow x = -3 - \\dfrac{1}{3} = \\dfrac{-10}{3} = -3\\dfrac{1}{3}$ <br\/> V\u1eady gi\u00e1 tr\u1ecb c\u1ee7a $x$ l\u00e0 $x \\in \\left\\{ 2\\dfrac{2}{3}; -3\\dfrac{1}{3} \\right\\} $ <br\/> <br\/> <span class='basic_pink'> \u0110\u00e1p \u00e1n \u0111\u00fang l\u00e0 A. <\/span><\/span> ","column":2}]}],"id_ques":512},{"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/lop7/toan/daiso/bai11/lv1/img\/2.jpg' \/><\/center> T\u00ecm $x $ bi\u1ebft: $|x| = 2,5$ ","select":["A. $x = 2,5$ ","B. $x = -2,5$ ","C. $x = \\pm 2,5$","D. $x = \\varnothing $"],"explain":" Ta c\u00f3: $|x| = 2,5$ <br\/> Suy ra: $x = \\pm 2,5$ <br\/> <br\/> <span class='basic_pink'> \u0110\u00e1p \u00e1n \u0111\u00fang l\u00e0 C. <\/span><\/span> ","column":2}]}],"id_ques":513},{"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/lop7/toan/daiso/bai11/lv1/img\/2.jpg' \/><\/center> T\u00ecm $x $ bi\u1ebft: $|x - 1| = 2 $ ","select":["A. $x = 3$ ","B. $x = 3$ ho\u1eb7c $x = -1$","C. $x = 1$ ","D. $x = -3$ ho\u1eb7c $x = -1$"],"explain":" <span class='basic_left'><span class='basic_green'>H\u01b0\u1edbng d\u1eabn:<\/span> <br\/> N\u1ebfu $|x| = a$ (v\u1edbi $a \\geq 0$) <br\/> th\u00ec $x = \\pm a $ <br\/> <span class='basic_green'>B\u00e0i gi\u1ea3i:<\/span><br\/> Ta c\u00f3: $|x - 1| = 2 \\\\ \\Rightarrow x - 1 = \\pm 2 $ <br\/> Tr\u01b0\u1eddng h\u1ee3p 1: $x - 1 = 2 \\Rightarrow x = 2 + 1 = 3$ <br\/> Tr\u01b0\u1eddng h\u1ee3p 2: $x - 1 = -2 \\Rightarrow x = -2 + 1 = -1 $ <br\/> V\u1eady gi\u00e1 tr\u1ecb c\u1ee7a $x$ l\u00e0 $x \\in \\{ 3; -1 \\}$ <br\/> <br\/> <span class='basic_pink'> \u0110\u00e1p \u00e1n \u0111\u00fang l\u00e0 B. <\/span><\/span> ","column":2}]}],"id_ques":514},{"time":9,"part":[{"title":"\u0110i\u1ec1n s\u1ed1 th\u00edch h\u1ee3p v\u00e0o ch\u1ed7 tr\u1ed1ng","title_trans":"","temp":"fill_the_blank","correct":[[["-43"],["49"]]],"list":[{"point":5,"width":50,"type_input":"","input_hint":["sqrt","frac"],"ques":" <center><img src='https://www.luyenthi123.com/file/luyenthi123/lop7/toan/daiso/bai11/lv1/img\/2.jpg' \/><\/center> T\u00ecm $x$ bi\u1ebft $ 1\\dfrac{2}{5}.x + \\dfrac{3}{7} = \\dfrac{-4}{5}$ <br\/> <b> \u0110\u00e1p s\u1ed1: <\/b> $x = $ <div class=\"frac123\"><div class=\"ts\">_input_<\/div><div class=\"ms\">_input_<\/div><\/div>","explain":" <span class='basic_left'><span class='basic_green'>H\u01b0\u1edbng d\u1eabn:<\/span> <br\/> <b> B\u00e0i to\u00e1n t\u00ecm x <\/b> <br\/> - Chuy\u1ec3n c\u00e1c h\u1ea1ng t\u1eed ch\u1ee9a x sang m\u1ed9t v\u1ebf, c\u00e1c h\u1eb1ng s\u1ed1 sang v\u1ebf kia. <br\/> - Thu g\u1ecdn v\u00e0 t\u00ecm x. <\/span> <br\/> <br\/> <span class='basic_green'>B\u00e0i gi\u1ea3i:<\/span><br\/> Ta c\u00f3: $ 1\\dfrac{2}{5}.x + \\dfrac{3}{7} = \\dfrac{-4}{5} \\\\ \\Rightarrow 1\\dfrac{2}{5}.x = \\dfrac{-4}{5} - \\dfrac{3}{7} \\\\ \\Rightarrow \\dfrac{7}{5}.x = -\\left(\\dfrac{4}{5} + \\dfrac{3}{7}\\right) = -\\dfrac{43}{35} \\\\ \\Rightarrow x = \\dfrac{-43}{35} : \\dfrac{7}{5} \\\\ \\Rightarrow x = \\dfrac{-43}{49}$ <\/span>"}]}],"id_ques":515},{"time":9,"part":[{"title":"\u0110i\u1ec1n s\u1ed1 th\u00edch h\u1ee3p v\u00e0o ch\u1ed7 tr\u1ed1ng","title_trans":"","temp":"fill_the_blank","correct":[[["-7"],["11"]]],"list":[{"point":5,"width":50,"type_input":"","input_hint":["sqrt","frac"],"ques":" <center><img src='https://www.luyenthi123.com/file/luyenthi123/lop7/toan/daiso/bai11/lv1/img\/2.jpg' \/><\/center> T\u00ecm $x$ bi\u1ebft $ \\dfrac{-11}{12}.x + 0,25 = \\dfrac{5}{6}$ <br\/> <b> \u0110\u00e1p s\u1ed1: <\/b> $x = $ <div class=\"frac123\"><div class=\"ts\">_input_<\/div><div class=\"ms\">_input_<\/div><\/div>","explain":" <span class='basic_left'><span class='basic_green'>H\u01b0\u1edbng d\u1eabn:<\/span> <br\/> <b> B\u00e0i to\u00e1n t\u00ecm x <\/b> <br\/> - Chuy\u1ec3n c\u00e1c h\u1ea1ng t\u1eed ch\u1ee9a x sang m\u1ed9t v\u1ebf, c\u00e1c h\u1eb1ng s\u1ed1 sang v\u1ebf kia. <br\/> - Thu g\u1ecdn v\u00e0 t\u00ecm x. <\/span> <br\/> <br\/> <span class='basic_green'>B\u00e0i gi\u1ea3i:<\/span><br\/> Ta c\u00f3: $ \\dfrac{-11}{12}.x + 0,25 = \\dfrac{5}{6} \\\\ \\Rightarrow \\dfrac{-11}{12}.x = \\dfrac{5}{6} - \\dfrac{1}{4} \\\\ \\Rightarrow \\dfrac{-11}{12}.x = \\dfrac{7}{12} \\\\ \\Rightarrow x = \\dfrac{7}{12} : \\dfrac{-11}{12} \\\\ \\Rightarrow x = \\dfrac{-7}{11}$<\/span> "}]}],"id_ques":516},{"time":24,"part":[{"title":"\u0110i\u1ec1n \u0111\u00e1p \u00e1n \u0111\u00fang v\u00e0o \u00f4 tr\u1ed1ng","title_trans":"","temp":"fill_the_blank","correct":[[["-6"]]],"list":[{"point":5,"width":50,"type_input":"","ques":"Th\u1ef1c hi\u1ec7n ph\u00e9p t\u00ednh: <br\/> $ A = \\dfrac{3}{7}.19\\dfrac{1}{3} - \\dfrac{3}{7}.33\\dfrac{1}{3} $ = _input_","hint":"\u00c1p d\u1ee5ng: $ab - ac = a(b - c)$","explain":" Ta c\u00f3: $A = \\dfrac{3}{7}.19\\dfrac{1}{3} - \\dfrac{3}{7}.33\\dfrac{1}{3} \\\\ = \\dfrac{3}{7}.\\left(19\\dfrac{1}{3} - 33\\dfrac{1}{3}\\right) \\\\ = \\dfrac{3}{7}.\\left( 19 + \\dfrac{1}{3} - 33 - \\dfrac{1}{3} \\right) \\\\ = \\dfrac{3}{7}.(-14) \\\\ = -6 $ <br\/> <br\/> <span class='basic_pink'> K\u1ebft qu\u1ea3 ph\u00e9p t\u00ednh l\u00e0 -6. <\/span><\/span>"}]}],"id_ques":517},{"time":24,"part":[{"title":"\u0110i\u1ec1n \u0111\u00e1p \u00e1n \u0111\u00fang v\u00e0o \u00f4 tr\u1ed1ng","title_trans":"","temp":"fill_the_blank","correct":[[["0"]]],"list":[{"point":5,"width":50,"type_input":"","ques":"Th\u1ef1c hi\u1ec7n ph\u00e9p t\u00ednh: <br\/> $ B = 9.\\left(\\dfrac{-1}{3}\\right)^{3} + \\dfrac{1}{3} $= _input_","explain":" Ta c\u00f3: $B = 9.\\left(\\dfrac{-1}{3}\\right)^{3} + \\dfrac{1}{3} \\\\ = 9.\\left(\\dfrac{-1}{27}\\right) + \\dfrac{1}{3} \\\\ = \\dfrac{-1}{3} + \\dfrac{1}{3} \\\\ = 0 $ <br\/> <br\/> <span class='basic_pink'> K\u1ebft qu\u1ea3 ph\u00e9p t\u00ednh l\u00e0 0. <\/span><\/span>"}]}],"id_ques":518},{"time":24,"part":[{"title":"\u0110i\u1ec1n \u0111\u00e1p \u00e1n \u0111\u00fang v\u00e0o \u00f4 tr\u1ed1ng","title_trans":"","temp":"fill_the_blank","correct":[[["5,3"]]],"list":[{"point":5,"width":50,"type_input":"","ques":" T\u00ednh nhanh M = (-0,125) . (-5,3) . 8 = _input_","hint":"Nh\u00f3m s\u1ed1 h\u1ea1ng th\u00edch h\u1ee3p r\u1ed3i th\u1ef1c hi\u1ec7n ph\u00e9p t\u00ednh.","explain":" Ta c\u00f3: $M = (-0,125) . (-5,3) . 8 \\\\ = [(-0,125).8].(-5,3) \\\\ = (-1).(-5,3) \\\\ = 5,3 $ <br\/> <br\/> <span class='basic_pink'> K\u1ebft qu\u1ea3 ph\u00e9p t\u00ednh l\u00e0 5,3. <\/span><\/span>"}]}],"id_ques":519},{"time":24,"part":[{"title":"\u0110i\u1ec1n \u0111\u00e1p \u00e1n \u0111\u00fang v\u00e0o \u00f4 tr\u1ed1ng","title_trans":"","temp":"fill_the_blank","correct":[[["-79"]]],"list":[{"point":5,"width":50,"type_input":"","ques":" T\u00ednh nhanh N = (-2,5) . (-4) . (-7,9) = _input_","hint":"Nh\u00f3m s\u1ed1 h\u1ea1ng th\u00edch h\u1ee3p r\u1ed3i th\u1ef1c hi\u1ec7n ph\u00e9p t\u00ednh.","explain":" Ta c\u00f3: $M = (-2,5) . (-4) . (-7,9) \\\\ = [(-2,5).(-4)].(-7,9) \\\\ = 10.(-7,9) \\\\ = -79 $ <br\/> <br\/> <span class='basic_pink'> K\u1ebft qu\u1ea3 ph\u00e9p t\u00ednh l\u00e0 -79. <\/span><\/span>"}]}],"id_ques":520}],"lesson":{"save":0,"level":1}}