{"segment":[{"time":24,"part":[{"title":"\u0110i\u1ec1n s\u1ed1 th\u00edch h\u1ee3p v\u00e0o ch\u1ed7 tr\u1ed1ng ","title_trans":"","temp":"fill_the_blank","correct":[[["768"]]],"list":[{"point":5,"width":50,"type_input":"","ques":" <span class='basic_left'> Nh\u00e2n vi\u00ean vi t\u00ednh A c\u00f3 th\u1ec3 \u0111\u00e1nh \u0111\u01b0\u1ee3c 160 t\u1eeb trong 2,5 ph\u00fat. Trong 12 ph\u00fat nh\u00e2n vi\u00ean \u0111\u00f3 \u0111\u00e1nh \u0111\u01b0\u1ee3c bao nhi\u00eau t\u1eeb? <br\/> <b> \u0110\u00e1p s\u1ed1: <\/b> _input_ (t\u1eeb) <\/span> <br\/> ","hint":"L\u1eadp c\u00e1c t\u1ec9 s\u1ed1 t\u01b0\u01a1ng \u1ee9ng c\u1ee7a hai \u0111\u1ea1i l\u01b0\u1ee3ng. ","explain":"<span class='basic_left'><span class='basic_green'>H\u01b0\u1edbng d\u1eabn:<\/span><br\/> B\u01b0\u1edbc 1: X\u00e1c \u0111\u1ecbnh quan h\u1ec7 t\u1ec9 l\u1ec7 thu\u1eadn gi\u1eefa hai \u0111\u1ea1i l\u01b0\u1ee3ng $y$ v\u00e0 $x$ <br\/> B\u01b0\u1edbc 2: \u00c1p d\u1ee5ng t\u00ednh ch\u1ea5t t\u1ec9 s\u1ed1 hai gi\u00e1 tr\u1ecb b\u1ea5t k\u00ec c\u1ee7a \u0111\u1ea1i l\u01b0\u1ee3ng n\u00e0y b\u1eb1ng t\u1ec9 s\u1ed1 hai gi\u00e1 tr\u1ecb t\u01b0\u01a1ng \u1ee9ng c\u1ee7a \u0111\u1ea1i l\u01b0\u1ee3ng kia. <\/span><br\/><br\/> <span class='basic_left'> T\u00f3m t\u1eaft \u0111\u1ec1 b\u00e0i: <br\/> S\u1ed1 t\u1eeb $ \\qquad$ Th\u1eddi gian <br\/> 160 t\u1eeb $\\hspace{1cm}$ 2,5 ph\u00fat <br\/> $x$ t\u1eeb ? $\\hspace{1cm}$ 12 ph\u00fat <\/span> <br\/> <span class='basic_green'>B\u00e0i gi\u1ea3i:<\/span> <br\/> Ta c\u00f3 th\u1eddi gian v\u00e0 s\u1ed1 t\u1eeb \u0111\u00e1nh \u0111\u01b0\u1ee3c l\u00e0 hai \u0111\u1ea1i l\u01b0\u1ee3ng t\u1ec9 l\u1ec7 thu\u1eadn. <br\/> Theo t\u00ednh ch\u1ea5t c\u1ee7a hai \u0111\u1ea1i l\u01b0\u1ee3ng t\u1ec9 l\u1ec7 thu\u1eadn, ta c\u00f3: $ \\dfrac{160}{x} = \\dfrac{2,5}{12} $ <br\/> Suy ra: $ x = \\dfrac{160.12}{2,5} = 768 $ <br\/> V\u1eady s\u1ed1 t\u1eeb \u0111\u00e1nh \u0111\u01b0\u1ee3c trong 12 ph\u00fat l\u00e0: 768 (t\u1eeb) <br\/><span class='basic_pink'> \u0110\u00e1p s\u1ed1 l\u00e0 768. <\/span> "}]}],"id_ques":561},{"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'> Cho $x$ v\u00e0 $y$ l\u00e0 hai \u0111\u1ea1i l\u01b0\u1ee3ng t\u1ec9 l\u1ec7 thu\u1eadn v\u00e0 khi $x$ = 12 th\u00ec $y$ = 4. H\u1ec7 s\u1ed1 t\u1ec9 l\u1ec7 $k$ c\u1ee7a $y$ \u0111\u1ed1i v\u1edbi $x$ l\u00e0? <\/span>","select":["A. 3 ","B. 8 ","C. 16 ","D. $\\dfrac{1}{3}$ "],"explain":" <span class='basic_left'><span class='basic_green'>H\u01b0\u1edbng d\u1eabn:<\/span><br\/> X\u00e1c \u0111\u1ecbnh h\u1ec7 s\u1ed1 t\u1ec9 l\u1ec7 $k$ gi\u1eefa $y$ v\u00e0 $x$; $k = \\dfrac{y}{x}$ <\/span> <br\/><br\/><span class='basic_green'>B\u00e0i gi\u1ea3i:<\/span> <br\/> V\u00ec $x$ v\u00e0 $y$ l\u00e0 hai \u0111\u1ea1i l\u01b0\u1ee3ng t\u1ec9 l\u1ec7 thu\u1eadn n\u00ean $y = kx$; ($k$ l\u00e0 h\u1eb1ng s\u1ed1, $k \\neq 0$) <br\/> v\u00e0 theo \u0111i\u1ec1u ki\u1ec7n $x$ = 12 th\u00ec $y$ = 4 n\u00ean thay v\u00e0o ta t\u00ednh \u0111\u01b0\u1ee3c: <br\/> $k = \\dfrac{4}{12} = \\dfrac{1}{3} $ <br\/><br\/><span class='basic_pink'> \u0110\u00e1p \u00e1n \u0111\u00fang l\u00e0 D. <\/span><\/span> ","column":2}]}],"id_ques":562},{"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":" \u0110\u1ea1i l\u01b0\u1ee3ng x t\u1ec9 l\u1ec7 thu\u1eadn v\u1edbi \u0111\u1ea1i l\u01b0\u1ee3ng y. N\u1ebfu y t\u0103ng l\u00ean 5 l\u1ea7n th\u00ec: ","select":["A. x gi\u1ea3m \u0111i 5 l\u1ea7n ","B. x t\u0103ng l\u00ean 5 l\u1ea7n ","C. x t\u0103ng l\u00ean 10 l\u1ea7n","D. x kh\u00f4ng t\u0103ng c\u0169ng kh\u00f4ng gi\u1ea3m "],"explain":" V\u00ec x, y l\u00e0 hai \u0111\u1ea1i l\u01b0\u1ee3ng t\u1ec9 l\u1ec7 thu\u1eadn n\u00ean $y = kx \\Leftrightarrow x = \\frac{y}{k}$ <br\/> Suy ra n\u1ebfu $y$ t\u0103ng l\u00ean $5$ l\u1ea7n th\u00ec $x$ c\u0169ng t\u0103ng l\u00ean $5$ l\u1ea7n. <br\/><br\/><span class='basic_pink'> \u0110\u00e1p \u00e1n \u0111\u00fang l\u00e0 B. <\/span><\/span> ","column":2}]}],"id_ques":563},{"time":24,"part":[{"title":"\u0110i\u1ec1n s\u1ed1 th\u00edch h\u1ee3p v\u00e0o ch\u1ed7 tr\u1ed1ng ","title_trans":"","temp":"fill_the_blank","correct":[[["3"]]],"list":[{"point":5,"width":50,"type_input":"","ques":" <span class='basic_left'> M\u1ed9t \u00f4 t\u00f4 ch\u1ea1y qu\u00e3ng \u0111\u01b0\u1eddng 225 km trong 4,5 gi\u1edd. V\u1edbi v\u1eadn t\u1ed1c \u0111\u00f3 th\u00ec xe ch\u1ea1y 150km trong bao l\u00e2u? <\/span> <br\/> \u0110\u00e1p s\u1ed1: $\\FormInput[40][bl_elm_true basic_elm basic_blank basic_blank_part]{} (gi\u1edd) $","hint":"L\u1eadp c\u00e1c t\u1ec9 s\u1ed1 t\u01b0\u01a1ng \u1ee9ng c\u1ee7a hai \u0111\u1ea1i l\u01b0\u1ee3ng. ","explain":"<span class='basic_left'><span class='basic_green'>H\u01b0\u1edbng d\u1eabn:<\/span><br\/> B\u01b0\u1edbc 1: X\u00e1c \u0111\u1ecbnh quan h\u1ec7 t\u1ec9 l\u1ec7 thu\u1eadn gi\u1eefa hai \u0111\u1ea1i l\u01b0\u1ee3ng $y$ v\u00e0 $x$ <br\/> B\u01b0\u1edbc 2: \u00c1p d\u1ee5ng t\u00ednh ch\u1ea5t t\u1ec9 s\u1ed1 hai gi\u00e1 tr\u1ecb b\u1ea5t k\u00ec c\u1ee7a \u0111\u1ea1i l\u01b0\u1ee3ng n\u00e0y b\u1eb1ng t\u1ec9 s\u1ed1 hai gi\u00e1 tr\u1ecb t\u01b0\u01a1ng \u1ee9ng c\u1ee7a \u0111\u1ea1i l\u01b0\u1ee3ng kia. <\/span> <br\/> <br\/><span class='basic_left'> T\u00f3m t\u1eaft \u0111\u1ec1 b\u00e0i: <br\/> Qu\u00e3ng \u0111\u01b0\u1eddng $ \\qquad$ Th\u1eddi gian <br\/> $ \\quad$ 225 km $\\hspace{1,5cm}$ 4,5 gi\u1edd <br\/> $ \\quad$ 150 km $\\hspace{1,5cm}$ $x$ gi\u1edd ? <\/span> <span class='basic_green'>B\u00e0i gi\u1ea3i:<\/span> <br\/> V\u1edbi c\u00f9ng m\u1ed9t v\u1eadn t\u1ed1c th\u00ec qu\u00e3ng \u0111\u01b0\u1eddng v\u00e0 th\u1eddi gian xe ch\u1ea1y l\u00e0 hai \u0111\u1ea1i l\u01b0\u1ee3ng t\u1ec9 l\u1ec7 thu\u1eadn. <br\/> Theo t\u00ednh ch\u1ea5t c\u1ee7a hai \u0111\u1ea1i l\u01b0\u1ee3ng t\u1ec9 l\u1ec7 thu\u1eadn, ta c\u00f3: $ \\dfrac{225}{150} = \\dfrac{4,5}{x} $ <br\/> Suy ra: $ x = \\dfrac{150.4,5}{225} = 3 $ <br\/> V\u1eady xe ch\u1ea1y 150 km h\u1ebft 3 gi\u1edd. <\/span> <br\/><br\/><span class='basic_pink'> V\u1eady s\u1ed1 c\u1ea7n \u0111i\u1ec1n l\u00e0 3 <\/span> "}]}],"id_ques":564},{"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'> T\u00ecm ba s\u1ed1 a, b, c n\u1ebfu bi\u1ebft a, b, c t\u1ec9 l\u1ec7 thu\u1eadn v\u1edbi 7, 3, 11 v\u00e0 a + b + c = 105.<\/span>","select":["A. a = 35, b = 15, c = 50 ","B. a = 35, b = 25, c = 55 ","C. a = 28, b = 12, c = 44 ","D. a = 35, b = 15, c = 55 "],"hint":"\u00c1p d\u1ee5ng t\u00ednh ch\u1ea5t d\u00e3y t\u1ec9 s\u1ed1 b\u1eb1ng nhau.","explain":"<span class='basic_left'><span class='basic_green'>H\u01b0\u1edbng d\u1eabn:<\/span><br\/> B\u01b0\u1edbc 1: L\u1eadp d\u00e3y t\u1ec9 s\u1ed1 b\u1eb1ng nhau. <br\/> B\u01b0\u1edbc 2: V\u1eadn d\u1ee5ng t\u00ednh ch\u1ea5t c\u1ee7a d\u00e3y t\u1ec9 s\u1ed1 b\u1eb1ng nhau \u0111\u1ec3 t\u00ecm $a, b, c$ <\/span> <br\/><br\/><span class='basic_green'>B\u00e0i gi\u1ea3i:<\/span> <br\/> Ta c\u00f3 a, b, c t\u1ec9 l\u1ec7 thu\u1eadn v\u1edbi 7, 3, 11 suy ra $\\dfrac{a}{7} = \\dfrac{b}{3} = \\dfrac{c}{11} $ <br\/> \u00c1p d\u1ee5ng t\u00ednh ch\u1ea5t d\u00e3y t\u1ec9 s\u1ed1 b\u1eb1ng nhau ta \u0111\u01b0\u1ee3c: <br\/> $ \\dfrac{a}{7} = \\dfrac{b}{3} = \\dfrac{c}{11} = \\dfrac{a+b+c}{7+3+11} = \\dfrac{105}{21} = 5 $ <br\/> Do \u0111\u00f3: $a = 7.5 = 35 \\\\ b = 3.5 = 15 \\\\ c = 11.5 = 55 $ <br\/><br\/><span class='basic_pink'> \u0110\u00e1p \u00e1n \u0111\u00fang l\u00e0 D. <\/span><\/span> ","column":2}]}],"id_ques":565},{"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'> Chia s\u1ed1 99 th\u00e0nh ba ph\u1ea7n t\u1ec9 l\u1ec7 thu\u1eadn v\u1edbi 2, 3, 4. Gi\u00e1 tr\u1ecb c\u1ee7a m\u1ed7i ph\u1ea7n l\u00e0: <\/span>","select":["A. 22, 33, 44 ","B. 20, 30, 40 ","C. 33, 30, 36","D. M\u1ed9t k\u1ebft qu\u1ea3 kh\u00e1c "],"hint":"\u0110\u1eb7t \u1ea9n ph\u1ee5 r\u1ed3i \u00e1p d\u1ee5ng t\u00ednh ch\u1ea5t d\u00e3y t\u1ec9 s\u1ed1 b\u1eb1ng nhau.","explain":"<span class='basic_left'><span class='basic_green'>H\u01b0\u1edbng d\u1eabn:<\/span><br\/> B\u01b0\u1edbc 1: L\u1eadp d\u00e3y t\u1ec9 s\u1ed1 b\u1eb1ng nhau: $ \\dfrac{x}{a} = \\dfrac{y}{b} = \\dfrac{z}{c} $ trong \u0111\u00f3 $ x + y + z = M$ <br\/> B\u01b0\u1edbc 2: V\u1eadn d\u1ee5ng t\u00ednh ch\u1ea5t c\u1ee7a d\u00e3y t\u1ec9 s\u1ed1 b\u1eb1ng nhau \u0111\u1ec3 t\u00ecm $x, y, z$ <br\/><span class='basic_green'>B\u00e0i gi\u1ea3i:<\/span> <br\/> <span class='basic_left'> G\u1ecdi ba ph\u1ea7n c\u1ea7n t\u00ecm l\u00e0 $x, y, z$ <br\/> Theo \u0111\u1ec1 b\u00e0i ta c\u00f3: $ \\dfrac{x}{2} = \\dfrac{y}{3} = \\dfrac{z}{4} $ v\u00e0 $ x + y + z = 99 $ <br\/> \u00c1p d\u1ee5ng t\u00ednh ch\u1ea5t d\u00e3y t\u1ec9 s\u1ed1 b\u1eb1ng nhau ta c\u00f3: <br\/> $ \\dfrac{x}{2} = \\dfrac{y}{3} = \\dfrac{z}{4} = \\dfrac{x+y+z}{2+3+4} = \\dfrac{99}{9} = 11 $ <br\/> Do \u0111\u00f3: $x = 2.11 = 22 \\\\ y = 3.11 = 33 \\\\ z = 4.11 = 44 $ <br\/> V\u1eady ba ph\u1ea7n c\u1ea7n t\u00ecm l\u00e0 22; 33; 44 <br\/><span class='basic_pink'> \u0110\u00e1p \u00e1n \u0111\u00fang l\u00e0 A. <\/span><\/span> ","column":2}]}],"id_ques":566},{"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'> Cho $x$ v\u00e0 $y$ l\u00e0 hai \u0111\u1ea1i l\u01b0\u1ee3ng t\u1ec9 l\u1ec7 thu\u1eadn v\u00e0 khi $x$ = 4 th\u00ec $y$ = 9. T\u00ednh gi\u00e1 tr\u1ecb c\u1ee7a $x$ khi $y$ b\u1eb1ng -6? <\/span>","select":["A. $\\dfrac{-8}{3} $ ","B. -13,5 ","C. -30 ","D. -78 "],"hint":"- T\u00ecm h\u1ec7 s\u1ed1 t\u1ec9 l\u1ec7 $k$ <br\/> - Thay v\u00e0o c\u00f4ng th\u1ee9c r\u1ed3i t\u00ecm $x$","explain":" <span class='basic_left'><span class='basic_green'>H\u01b0\u1edbng d\u1eabn:<\/span><br\/> B\u01b0\u1edbc 1: X\u00e1c \u0111\u1ecbnh h\u1ec7 s\u1ed1 t\u1ec9 l\u1ec7 $k$ gi\u1eefa $y$ v\u00e0 $x$; $k = \\dfrac{y}{x}$ <br\/> B\u01b0\u1edbc 2: T\u00ecm $x$ theo c\u00f4ng th\u1ee9c $x = \\dfrac{y}{k} $ <\/span> <br\/><br\/><span class='basic_green'>B\u00e0i gi\u1ea3i:<\/span> <br\/> V\u00ec $x$ v\u00e0 $y$ l\u00e0 hai \u0111\u1ea1i l\u01b0\u1ee3ng t\u1ec9 l\u1ec7 thu\u1eadn n\u00ean $y = kx$; ($k$ l\u00e0 h\u1eb1ng s\u1ed1, $k \\neq 0$) <br\/> v\u00e0 theo \u0111i\u1ec1u ki\u1ec7n $x$ = 4 th\u00ec $y$ = 9 n\u00ean thay v\u00e0o ta t\u00ednh \u0111\u01b0\u1ee3c : $k = \\dfrac{9}{4} $ <br\/> Do \u0111\u00f3, khi $y$ = -6 th\u00ec $x = (-6) : \\dfrac{9}{4} = \\dfrac{-8}{3} $ <br\/><br\/><span class='basic_pink'> \u0110\u00e1p \u00e1n \u0111\u00fang l\u00e0 A. <\/span><\/span> ","column":2}]}],"id_ques":567},{"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'> \u0110\u1ed9 d\u00e0i ba c\u1ea1nh c\u1ee7a m\u1ed9t tam gi\u00e1c t\u1ec9 l\u1ec7 thu\u1eadn v\u1edbi 4, 6, 8. Bi\u1ebft r\u1eb1ng chu vi tam gi\u00e1c l\u00e0 36 cm. T\u00ednh \u0111\u1ed9 d\u00e0i c\u1ea1nh l\u1edbn nh\u1ea5t c\u1ee7a tam gi\u00e1c \u0111\u00f3? <\/span>","select":["A. 8 cm ","B. 12 cm ","C. 16 cm ","D. 24 cm"],"hint":"\u0110\u1eb7t \u1ea9n ph\u1ee5 r\u1ed3i \u00e1p d\u1ee5ng t\u00ednh ch\u1ea5t d\u00e3y t\u1ec9 s\u1ed1 b\u1eb1ng nhau.","explain":"<span class='basic_left'><span class='basic_green'>H\u01b0\u1edbng d\u1eabn:<\/span><br\/> B\u01b0\u1edbc 1: L\u1eadp d\u00e3y t\u1ec9 s\u1ed1 b\u1eb1ng nhau: $ \\dfrac{x}{a} = \\dfrac{y}{b} = \\dfrac{z}{c} $ trong \u0111\u00f3 $ x + y + z = M$ <br\/> B\u01b0\u1edbc 2: V\u1eadn d\u1ee5ng t\u00ednh ch\u1ea5t c\u1ee7a d\u00e3y t\u1ec9 s\u1ed1 b\u1eb1ng nhau \u0111\u1ec3 t\u00ecm $x, y, z$ <br\/><span class='basic_green'>B\u00e0i gi\u1ea3i:<\/span> <br\/> <span class='basic_left'> G\u1ecdi \u0111\u1ed9 d\u00e0i c\u00e1c c\u1ea1nh c\u1ee7a tam gi\u00e1c l\u1ea7n l\u01b0\u1ee3t l\u00e0 $x, y, z$ (cm). <br\/> Theo \u0111\u1ec1 b\u00e0i ta c\u00f3: $ \\dfrac{x}{4} = \\dfrac{y}{6} = \\dfrac{z}{8} $ v\u00e0 $ x + y + z = 36 $ <br\/> \u00c1p d\u1ee5ng t\u00ednh ch\u1ea5t d\u00e3y t\u1ec9 s\u1ed1 b\u1eb1ng nhau ta c\u00f3: <br\/> $ \\dfrac{x}{4} = \\dfrac{y}{6} = \\dfrac{z}{8} = \\dfrac{x+y+z}{4+6+8} = \\dfrac{36}{18} = 2 $ <br\/> Do \u0111\u00f3: $x = 4.2 = 8 \\\\ y = 6.2 = 12 \\\\ z = 8.2 = 16 $ <br\/> V\u1eady \u0111\u1ed9 d\u00e0i l\u1edbn nh\u1ea5t l\u00e0 16 cm <br\/><span class='basic_pink'> \u0110\u00e1p \u00e1n \u0111\u00fang l\u00e0 C. <\/span><\/span> ","column":2}]}],"id_ques":568},{"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'> Cho bi\u1ebft 3 m\u00e9t d\u00e2y k\u1ebdm n\u1eb7ng 90 gam; $x$ m\u00e9t d\u00e2y k\u1ebdm nh\u01b0 v\u1eady n\u1eb7ng $y$ gam. Bi\u1ec3u di\u1ec5n $y$ theo $x$ l\u00e0: <\/span>","select":["A. $ y = 30 x$ ","B. $ y = \\dfrac{1}{30} x$ ","C. $ x = 30 y$","D. $ y = 30 + x$ "],"hint":"L\u1eadp c\u00e1c t\u1ec9 s\u1ed1 t\u01b0\u01a1ng \u1ee9ng c\u1ee7a hai \u0111\u1ea1i l\u01b0\u1ee3ng. ","explain":"<span class='basic_left'><span class='basic_green'>H\u01b0\u1edbng d\u1eabn:<\/span><br\/> B\u01b0\u1edbc 1: X\u00e1c \u0111\u1ecbnh quan h\u1ec7 t\u1ec9 l\u1ec7 thu\u1eadn gi\u1eefa hai \u0111\u1ea1i l\u01b0\u1ee3ng $y$ v\u00e0 $x$ <br\/> B\u01b0\u1edbc 2: \u00c1p d\u1ee5ng t\u00ednh ch\u1ea5t t\u1ec9 s\u1ed1 hai gi\u00e1 tr\u1ecb b\u1ea5t k\u00ec c\u1ee7a \u0111\u1ea1i l\u01b0\u1ee3ng n\u00e0y b\u1eb1ng t\u1ec9 s\u1ed1 hai gi\u00e1 tr\u1ecb t\u01b0\u01a1ng \u1ee9ng c\u1ee7a \u0111\u1ea1i l\u01b0\u1ee3ng kia. <br\/><br\/>T\u00f3m t\u1eaft \u0111\u1ec1 b\u00e0i: <br\/> \u0110\u1ed9 d\u00e0i d\u00e2y $ \\qquad$ Kh\u1ed1i l\u01b0\u1ee3ng d\u00e2y <br\/> $ \\quad$ 3 m\u00e9t $\\hspace{2cm}$ 90 gam <br\/> $ \\quad$ $x$ m\u00e9t $\\hspace{2cm}$ $y$ gam ? <\/span> <br\/><span class='basic_green'>B\u00e0i gi\u1ea3i:<\/span> <br\/> V\u00ec kh\u1ed1i l\u01b0\u1ee3ng c\u1ee7a cu\u1ed9n d\u00e2y th\u00e9p t\u1ec9 l\u1ec7 thu\u1eadn v\u1edbi chi\u1ec1u d\u00e0i d\u00e2y n\u00ean: <br\/> Theo t\u00ednh ch\u1ea5t c\u1ee7a hai \u0111\u1ea1i l\u01b0\u1ee3ng t\u1ec9 l\u1ec7 thu\u1eadn ta c\u00f3: $ \\dfrac{3}{x} = \\dfrac{90}{y} $ <br\/> Suy ra: $ y = \\dfrac{90}{3}x = 30x $ <br\/><span class='basic_pink'> \u0110\u00e1p \u00e1n \u0111\u00fang l\u00e0 A <\/span> ","column":2}]}],"id_ques":569},{"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'> C\u1ee9 xay x\u00e1t 50 kg th\u00f3c th\u00ec \u0111\u01b0\u1ee3c 36 kg g\u1ea1o. H\u1ecfi n\u1ebfu xay x\u00e1t 175 kg th\u00f3c th\u00ec \u0111\u01b0\u1ee3c bao nhi\u00eau ki-l\u00f4-gam g\u1ea1o ? <\/span>","select":["A. 126 kg ","B. 243 kg ","C. 150 kg ","D. 200 kg "],"hint":"L\u1eadp c\u00e1c t\u1ec9 s\u1ed1 t\u01b0\u01a1ng \u1ee9ng c\u1ee7a hai \u0111\u1ea1i l\u01b0\u1ee3ng. ","explain":"<span class='basic_left'><span class='basic_green'>H\u01b0\u1edbng d\u1eabn:<\/span><br\/> B\u01b0\u1edbc 1: X\u00e1c \u0111\u1ecbnh quan h\u1ec7 t\u1ec9 l\u1ec7 thu\u1eadn gi\u1eefa hai \u0111\u1ea1i l\u01b0\u1ee3ng $y$ v\u00e0 $x$ <br\/> B\u01b0\u1edbc 2: \u00c1p d\u1ee5ng t\u00ednh ch\u1ea5t t\u1ec9 s\u1ed1 hai gi\u00e1 tr\u1ecb b\u1ea5t k\u00ec c\u1ee7a \u0111\u1ea1i l\u01b0\u1ee3ng n\u00e0y b\u1eb1ng t\u1ec9 s\u1ed1 hai gi\u00e1 tr\u1ecb t\u01b0\u01a1ng \u1ee9ng c\u1ee7a \u0111\u1ea1i l\u01b0\u1ee3ng kia. <br\/><br\/> T\u00f3m t\u1eaft \u0111\u1ec1 b\u00e0i: <br\/> Kh\u1ed1i l\u01b0\u1ee3ng th\u00f3c $ \\qquad$ Kh\u1ed1i l\u01b0\u1ee3ng g\u1ea1o <br\/> $ \\quad$ 50 kg $\\hspace{3cm}$ 36 kg <br\/> $ \\quad$ 175 kg $\\hspace{3cm}$ $x$ kg ? <\/span> <span class='basic_green'>B\u00e0i gi\u1ea3i:<\/span> <br\/> Khi xay x\u00e1t th\u00ec kh\u1ed1i l\u01b0\u1ee3ng g\u1ea1o thu \u0111\u01b0\u1ee3c t\u1ec9 l\u1ec7 thu\u1eadn v\u1edbi kh\u1ed1i l\u01b0\u1ee3ng th\u00f3c \u0111em xay x\u00e1t. <br\/> Theo t\u00ednh ch\u1ea5t c\u1ee7a hai \u0111\u1ea1i l\u01b0\u1ee3ng t\u1ec9 l\u1ec7 thu\u1eadn ta c\u00f3: $ \\dfrac{50}{175} = \\dfrac{36}{x} $ <br\/> Suy ra: $ x = \\dfrac{175.36}{50} = 126 $ <br\/> V\u1eady n\u1ebfu xay x\u00e1t 175 kg th\u00f3c th\u00ec \u0111\u01b0\u1ee3c 126 kg g\u1ea1o <br\/><span class='basic_pink'> \u0110\u00e1p \u00e1n \u0111\u00fang l\u00e0 A <\/span><\/span> ","column":2}]}],"id_ques":570},{"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":"Cho bi\u1ebft \u0111\u1ea1i l\u01b0\u1ee3ng $y$ t\u1ec9 l\u1ec7 thu\u1eadn v\u1edbi \u0111\u1ea1i l\u01b0\u1ee3ng $x$ theo h\u1ec7 s\u1ed1 t\u1ec9 l\u1ec7 $k = \\dfrac{1}{2}. $ H\u00e3y bi\u1ec3u di\u1ec5n $y$ theo $x?$ ","select":["A. $y = \\dfrac{1}{2}x$ ","B. $y = \\dfrac{2}{x}$ ","C. $ y = 2x $ ","D. $xy = 2 $ "],"hint":"Xem \u0111\u1ecbnh ngh\u0129a.","explain":"<span class='basic_left'><span class='basic_green'>H\u01b0\u1edbng d\u1eabn:<\/span><br\/> \u0110\u1ea1i l\u01b0\u1ee3ng $y$ t\u1ec9 l\u1ec7 thu\u1eadn v\u1edbi \u0111\u1ea1i l\u01b0\u1ee3ng $x$ n\u00ean $y = kx$; ($k$ l\u00e0 h\u1eb1ng s\u1ed1, $k \\neq 0$) <\/span> <br\/><br\/><span class='basic_green'>B\u00e0i gi\u1ea3i:<\/span> <br\/> V\u00ec $y$ t\u1ec9 l\u1ec7 thu\u1eadn v\u1edbi $x$ theo h\u1ec7 s\u1ed1 t\u1ec9 l\u1ec7 $\\dfrac{1}{2}$ n\u00ean $y = \\dfrac{1}{2}x$ <br\/><br\/><span class='basic_pink'> \u0110\u00e1p \u00e1n \u0111\u00fang l\u00e0 A <\/span><\/span> ","column":2}]}],"id_ques":571},{"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":"C\u00e1c gi\u00e1 tr\u1ecb t\u01b0\u01a1ng \u1ee9ng c\u1ee7a $y$ v\u00e0 $x$ \u0111\u01b0\u1ee3c cho trong b\u1ea3ng sau: <table> <tr> <td> $x$ <\/td> <td> 2 <\/td> <td> 5 <\/td> <td> 8<\/td> <td>15 <\/td> <\/tr> <tr> <td> $y$ <\/td> <td> 14 <\/td> <td> 35 <\/td> <td> 56 <\/td> <td> 105 <\/td> <\/tr><\/table> H\u1ecfi hai \u0111\u1ea1i l\u01b0\u1ee3ng $y$ v\u00e0 $x$ c\u00f3 t\u1ec9 l\u1ec7 thu\u1eadn kh\u00f4ng? ","select":["C\u00f3 "," Kh\u00f4ng "],"hint":"T\u00ecm h\u1ec7 s\u1ed1 t\u1ec9 l\u1ec7 $k$ c\u1ee7a t\u1eebng c\u1ed9t r\u1ed3i so s\u00e1nh. ","explain":" <span class='basic_left'><span class='basic_green'>H\u01b0\u1edbng d\u1eabn:<\/span><br\/> X\u00e9t c\u00e1c t\u1ec9 s\u1ed1 t\u01b0\u01a1ng \u1ee9ng c\u1ee7a hai \u0111\u1ea1i l\u01b0\u1ee3ng, n\u1ebfu c\u00e1c t\u1ec9 s\u1ed1 b\u1eb1ng nhau th\u00ec hai \u0111\u1ea1i l\u01b0\u1ee3ng \u0111\u00f3 t\u1ec9 l\u1ec7 thu\u1eadn. <\/span> <br\/><br\/><span class='basic_green'>B\u00e0i gi\u1ea3i:<\/span> <br\/> Ta c\u00f3: $ \\dfrac{14}{2} = \\dfrac{35}{5} = \\dfrac{56}{8} = \\dfrac{105}{15} = 7$ <br\/> V\u1eady hai \u0111\u1ea1i l\u01b0\u1ee3ng $y$ v\u00e0 $x$ t\u1ec9 l\u1ec7 thu\u1eadn v\u1edbi nhau. <br\/><br\/><span class='basic_pink'> \u0110\u00e1p \u00e1n l\u00e0 C\u00f3. <\/span><\/span> ","column":2}]}],"id_ques":572},{"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'> Cho $y$ t\u1ec9 l\u1ec7 thu\u1eadn v\u1edbi $x$ theo h\u1ec7 s\u1ed1 t\u1ec9 l\u1ec7 $k = \\dfrac{1}{7} .$ Khi \u0111\u00f3 $x$ t\u1ec9 l\u1ec7 thu\u1eadn v\u1edbi $y$ theo h\u1ec7 s\u1ed1 t\u1ec9 l\u1ec7 l\u00e0: <\/span>","select":["A. $\\dfrac{-1}{7} $ ","B. -7 ","C. 7","D. 1 "],"explain":" <span class='basic_left'><span class='basic_green'>H\u01b0\u1edbng d\u1eabn:<\/span><br\/> Khi \u0111\u1ea1i l\u01b0\u1ee3ng $y$ t\u1ec9 l\u1ec7 thu\u1eadn v\u1edbi \u0111\u1ea1i l\u01b0\u1ee3ng $x$ theo h\u1ec7 s\u1ed1 t\u1ec9 l\u1ec7 $k$ <br\/> th\u00ec $x$ c\u0169ng t\u1ec9 l\u1ec7 thu\u1eadn v\u1edbi $y$ theo h\u1ec7 s\u1ed1 t\u1ec9 l\u1ec7 $\\dfrac{1}{k}. $ <\/span> <br\/><br\/><span class='basic_green'>B\u00e0i gi\u1ea3i:<\/span> <br\/> V\u00ec $y$ t\u1ec9 l\u1ec7 thu\u1eadn v\u1edbi $x$ theo h\u1ec7 s\u1ed1 t\u1ec9 l\u1ec7 $ \\dfrac{1}{7} $ n\u00ean $x$ t\u1ec9 l\u1ec7 thu\u1eadn v\u1edbi $y$ theo h\u1ec7 s\u1ed1 t\u1ec9 l\u1ec7 7. <br\/><br\/><span class='basic_pink'> \u0110\u00e1p \u00e1n \u0111\u00fang l\u00e0 C. <\/span><\/span> ","column":2}]}],"id_ques":573},{"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":"Hai \u0111\u1ea1i l\u01b0\u1ee3ng $x$ v\u00e0 $y$ t\u1ec9 l\u1ec7 thu\u1eadn v\u1edbi nhau, khi \u0111\u00f3 ta c\u00f3: ","select":["A. $xy = k $ ($k$ l\u00e0 h\u1eb1ng s\u1ed1) ","B. $ y = \\dfrac{k}{x} $ ($k$ l\u00e0 h\u1eb1ng s\u1ed1) ","C. $ y = kx $ ($k$ l\u00e0 h\u1eb1ng s\u1ed1, $k \\neq 0$) ","D. $x + y = k $ ($k$ l\u00e0 h\u1eb1ng s\u1ed1) "],"hint":"Xem \u0111\u1ecbnh ngh\u0129a.","explain":" V\u00ec $x$ v\u00e0 $y$ l\u00e0 hai \u0111\u1ea1i l\u01b0\u1ee3ng t\u1ec9 l\u1ec7 thu\u1eadn n\u00ean $y = kx$; ($k$ l\u00e0 h\u1eb1ng s\u1ed1, $k \\neq 0$) <br\/><br\/><span class='basic_pink'> \u0110\u00e1p \u00e1n \u0111\u00fang l\u00e0 C. <\/span><\/span> ","column":2}]}],"id_ques":574},{"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":"C\u00f4ng th\u1ee9c n\u00e0o sau \u0111\u00e2y cho ta quan h\u1ec7 t\u1ec9 l\u1ec7 thu\u1eadn gi\u1eefa $x$ v\u00e0 $y$? ","select":["A. $ 5yx = -1 $ ","B. $ xy = 20 $ ","C. $ y = \\dfrac{2017}{x} $ ","D. $y = \\dfrac{-3}{4}x $ "],"hint":"Xem \u0111\u1ecbnh ngh\u0129a.","explain":" V\u00ec $x$ v\u00e0 $y$ l\u00e0 hai \u0111\u1ea1i l\u01b0\u1ee3ng t\u1ec9 l\u1ec7 thu\u1eadn n\u00ean $y = kx$; ($k$ l\u00e0 h\u1eb1ng s\u1ed1, $k \\neq 0$) <br\/><br\/><span class='basic_pink'> Suy ra \u0111\u00e1p \u00e1n \u0111\u00fang l\u00e0 D. $y = \\dfrac{-3}{4}x $ <\/span><\/span> ","column":2}]}],"id_ques":575},{"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'> Cho $x$ v\u00e0 $y$ l\u00e0 hai \u0111\u1ea1i l\u01b0\u1ee3ng t\u1ec9 l\u1ec7 thu\u1eadn v\u00e0 khi $x$ = 5 th\u00ec $y$ = 15. H\u1ec7 s\u1ed1 t\u1ec9 l\u1ec7 $k$ c\u1ee7a $y$ \u0111\u1ed1i v\u1edbi $x$ l\u00e0? <\/span>","select":["A. 3 ","B. 75 ","C. $\\dfrac{1}{3}$","D. 10 "],"explain":" <span class='basic_left'><span class='basic_green'>H\u01b0\u1edbng d\u1eabn:<\/span><br\/> X\u00e1c \u0111\u1ecbnh h\u1ec7 s\u1ed1 t\u1ec9 l\u1ec7 $k$ gi\u1eefa $y$ v\u00e0 $x$; $k = \\dfrac{y}{x}$ <\/span> <br\/><br\/><span class='basic_green'>B\u00e0i gi\u1ea3i:<\/span> <br\/> V\u00ec $x$ v\u00e0 $y$ l\u00e0 hai \u0111\u1ea1i l\u01b0\u1ee3ng t\u1ec9 l\u1ec7 thu\u1eadn n\u00ean $y = kx$; ($k$ l\u00e0 h\u1eb1ng s\u1ed1, $k \\neq 0$) <br\/> v\u00e0 theo \u0111i\u1ec1u ki\u1ec7n $x$ = 5 th\u00ec $y$ = 15 n\u00ean thay v\u00e0o ta t\u00ednh \u0111\u01b0\u1ee3c: $k = \\dfrac{15}{5} = 3 $ <br\/><br\/><span class='basic_pink'> \u0110\u00e1p \u00e1n \u0111\u00fang l\u00e0 A. <\/span><\/span> ","column":2}]}],"id_ques":576},{"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'> Cho $x$ v\u00e0 $y$ l\u00e0 hai \u0111\u1ea1i l\u01b0\u1ee3ng t\u1ec9 l\u1ec7 thu\u1eadn v\u00e0 khi $x$ = 6 th\u00ec $y$ = 4. T\u00ednh gi\u00e1 tr\u1ecb c\u1ee7a $y$ khi $x$ b\u1eb1ng 9? <\/span>","select":["A. 2 ","B. 4 ","C. 6","D. 10 "],"hint":"- T\u00ecm h\u1ec7 s\u1ed1 t\u1ec9 l\u1ec7 $k$ <br\/> - Thay v\u00e0o c\u00f4ng th\u1ee9c r\u1ed3i t\u00ecm $y$","explain":" <span class='basic_left'><span class='basic_green'>H\u01b0\u1edbng d\u1eabn:<\/span><br\/> B\u01b0\u1edbc 1: X\u00e1c \u0111\u1ecbnh h\u1ec7 s\u1ed1 t\u1ec9 l\u1ec7 $k$ gi\u1eefa $y$ v\u00e0 $x$; $k = \\dfrac{y}{x}$ <br\/> B\u01b0\u1edbc 2: T\u00ecm $y$ theo c\u00f4ng th\u1ee9c $ y = kx $ <br\/><span class='basic_green'>B\u00e0i gi\u1ea3i:<\/span> <br\/> V\u00ec $x$ v\u00e0 $y$ l\u00e0 hai \u0111\u1ea1i l\u01b0\u1ee3ng t\u1ec9 l\u1ec7 thu\u1eadn n\u00ean $y = kx$; ($k$ l\u00e0 h\u1eb1ng s\u1ed1, $k \\neq 0$) <br\/> Theo \u0111i\u1ec1u ki\u1ec7n $x$ = 6 th\u00ec $y$ = 4 n\u00ean thay v\u00e0o ta t\u00ednh \u0111\u01b0\u1ee3c: $ k = \\dfrac{4}{6} = \\dfrac{2}{3} $ <br\/> Do \u0111\u00f3, khi $x$ = 9 th\u00ec $y = \\dfrac{2}{3}.9 = 6 $ <br\/><br\/><span class='basic_pink'> \u0110\u00e1p \u00e1n \u0111\u00fang l\u00e0 C. <\/span><\/span> ","column":2}]}],"id_ques":577},{"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'> Cho $x$ v\u00e0 $y$ l\u00e0 hai \u0111\u1ea1i l\u01b0\u1ee3ng t\u1ec9 l\u1ec7 thu\u1eadn v\u00e0 khi $x$ = 3 th\u00ec $y$ = -9. T\u00ednh gi\u00e1 tr\u1ecb c\u1ee7a $x$ khi $y$ b\u1eb1ng -12? <\/span>","select":["A. $\\dfrac{-4}{3} $ ","B. $\\dfrac{4}{3} $ ","C. -4","D. 4 "],"hint":"- T\u00ecm h\u1ec7 s\u1ed1 t\u1ec9 l\u1ec7 $k$ <br\/> - Thay v\u00e0o c\u00f4ng th\u1ee9c r\u1ed3i t\u00ecm $x$","explain":" <span class='basic_left'><span class='basic_green'>H\u01b0\u1edbng d\u1eabn:<\/span><br\/> B\u01b0\u1edbc 1: X\u00e1c \u0111\u1ecbnh h\u1ec7 s\u1ed1 t\u1ec9 l\u1ec7 $k$ gi\u1eefa $y$ v\u00e0 $x$; $k = \\dfrac{y}{x}$ <br\/> B\u01b0\u1edbc 2: T\u00ecm $x$ theo c\u00f4ng th\u1ee9c $x = \\dfrac{y}{k} $ <br\/><span class='basic_green'>B\u00e0i gi\u1ea3i:<\/span> <br\/> V\u00ec $x$ v\u00e0 $y$ l\u00e0 hai \u0111\u1ea1i l\u01b0\u1ee3ng t\u1ec9 l\u1ec7 thu\u1eadn n\u00ean $y = kx$; ($k$ l\u00e0 h\u1eb1ng s\u1ed1, $k \\neq 0$) <br\/> v\u00e0 theo \u0111i\u1ec1u ki\u1ec7n $x$ = 3 th\u00ec $y$ = -9 n\u00ean thay v\u00e0o ta t\u00ednh \u0111\u01b0\u1ee3c : <br\/> $k = \\dfrac{-9}{3} = -3 $ <br\/> Do \u0111\u00f3, khi $y$ = -12 th\u00ec $x = \\dfrac{-12}{-3} = 4 $ <br\/><br\/><span class='basic_pink'> \u0110\u00e1p \u00e1n \u0111\u00fang l\u00e0 D. <\/span><\/span> ","column":2}]}],"id_ques":578},{"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'> Bi\u1ebft $x, y$ l\u00e0 hai \u0111\u1ea1i l\u01b0\u1ee3ng t\u1ec9 l\u1ec7 thu\u1eadn v\u00e0 c\u00f3 c\u00e1c gi\u00e1 tr\u1ecb t\u01b0\u01a1ng \u1ee9ng cho \u1edf b\u1ea3ng sau: <\/span> <br\/> <table><tr><td>$x$ <\/td> <td> 5 <\/td> <td> 2 <\/td> <\/tr> <td> $y$ <\/td> <td> 10 <\/td> <td><span class='basic_hoi_black'>?<\/span> <\/td> <tr> <\/tr> <\/table> <br\/> K\u1ebft qu\u1ea3 \u1edf \u00f4 <span class='basic_hoi_black'>?<\/span> l\u00e0? ","select":["A. -4 ","B. 5 ","C. 2","D. 4 "],"hint":"+ T\u00ecm h\u1ec7 s\u1ed1 t\u1ec9 l\u1ec7 $k$ <br\/> + Thay v\u00e0o c\u00f4ng th\u1ee9c r\u1ed3i t\u00ecm $y$","explain":" <span class='basic_left'><span class='basic_green'>H\u01b0\u1edbng d\u1eabn:<\/span><br\/> B\u01b0\u1edbc 1: X\u00e1c \u0111\u1ecbnh h\u1ec7 s\u1ed1 t\u1ec9 l\u1ec7 $k$ gi\u1eefa $y$ v\u00e0 $x$; $k = \\dfrac{y}{x}$ <br\/> B\u01b0\u1edbc 2: T\u00ecm $y$ theo c\u00f4ng th\u1ee9c $ y = kx $ <\/span> <br\/><br\/><span class='basic_green'>B\u00e0i gi\u1ea3i:<\/span> <br\/> V\u00ec $x$ v\u00e0 $y$ l\u00e0 hai \u0111\u1ea1i l\u01b0\u1ee3ng t\u1ec9 l\u1ec7 thu\u1eadn n\u00ean: <br\/> $k = \\dfrac{y_{1}}{x_{1}} = \\dfrac{10}{5} = 2$ <br\/> Suy ra: $y_{2} = k.x_{2} = 2.2 = 4$ <br\/><br\/><span class='basic_pink'> \u0110\u00e1p \u00e1n \u0111\u00fang l\u00e0 D. <\/span><\/span> ","column":2}]}],"id_ques":579},{"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":[[["4"],["8"],["16"]]],"list":[{"point":5,"width":50,"type_input":"","ques":"Cho $x$ v\u00e0 $y$ l\u00e0 hai \u0111\u1ea1i l\u01b0\u1ee3ng t\u1ec9 l\u1ec7 thu\u1eadn. <br\/> \u0110i\u1ec1n s\u1ed1 th\u00edch h\u1ee3p v\u00e0o \u00f4 tr\u1ed1ng trong b\u1ea3ng sau: <table><tr><td>$x$<\/td><td>$x_{1} = 3$<\/td><td>$x_{2} = 6$<\/td><td>$x_{3} = 12$<\/td><td>$x_{4} = 24$<\/td><\/tr><tr><td>$y$<\/td><td>$y_{1} = 2$<\/td><td>$y_2$ = _input_<\/td><td>$y_3$ = _input_<\/td><td>$y_4$ = _input_<\/td><\/tr><\/table>","explain":" <span class='basic_left'><span class='basic_green'>H\u01b0\u1edbng d\u1eabn:<\/span><br\/> B\u01b0\u1edbc 1: X\u00e1c \u0111\u1ecbnh h\u1ec7 s\u1ed1 t\u1ec9 l\u1ec7 $k$ gi\u1eefa $y$ v\u00e0 $x$; $k = \\dfrac{y}{x}$ <br\/> B\u01b0\u1edbc 2: T\u00ecm $y$ theo c\u00f4ng th\u1ee9c $ y = kx $ <\/span> <br\/><br\/><span class='basic_green'>B\u00e0i gi\u1ea3i:<\/span> <br\/> V\u00ec $x$ v\u00e0 $y$ l\u00e0 hai \u0111\u1ea1i l\u01b0\u1ee3ng t\u1ec9 l\u1ec7 thu\u1eadn n\u00ean: $k = \\dfrac{y_{1}}{x_{1}} = \\dfrac{2}{3} $ <br\/> Suy ra: $y_{2} = k.x_{2} = \\dfrac{2}{3}.6 = 4; \\\\ y_{3} = k.x_{3} = \\dfrac{2}{3}.12 = 8; \\\\ y_{4} = k.x_{4} = \\dfrac{2}{3}.24 = 16 $ <br\/><br\/><span class='basic_pink'> \u0110\u00e1p \u00e1n c\u1ea7n \u0111i\u1ec1n l\u00e0 8; 16. <\/span><\/span> "}]}],"id_ques":580}],"lesson":{"save":0,"level":1}}