{"segment":[{"time":24,"part":[{"title":"L\u1ef1a ch\u1ecdn \u0111\u00fang hay sai","title_trans":"","temp":"true_false","correct":[["t","t","t","t"]],"list":[{"point":5,"ques":"C\u00e1c gi\u00e1 tr\u1ecb t\u01b0\u01a1ng \u1ee9ng c\u1ee7a hai \u0111\u1ea1i l\u01b0\u1ee3ng $x$ v\u00e0 $y$ \u0111\u01b0\u1ee3c cho trong b\u1ea3ng sau: <br\/> <table><tr><td>x<\/td><td>1<\/td><td>3<\/td><td>5<\/td><td>7<\/td><\/tr><tr><td>y<\/td><td>5<\/td><td>15<\/td><td>25<\/td><td>35<\/td><\/tr><\/table> <br\/> X\u00e9t c\u00e1c kh\u1eb3ng \u0111\u1ecbnh sau, kh\u1eb3ng \u0111\u1ecbnh n\u00e0o \u0111\u00fang, kh\u1eb3ng \u0111\u1ecbnh n\u00e0o sai? ","image":"","col_name":["","\u0110\u00fang","Sai"],"arr_ques":["\u0110\u1ea1i l\u01b0\u1ee3ng $y$ t\u1ec9 l\u1ec7 thu\u1eadn v\u1edbi \u0111\u1ea1i l\u01b0\u1ee3ng $x$","\u0110\u1ea1i l\u01b0\u1ee3ng $y$ l\u00e0 h\u00e0m s\u1ed1 c\u1ee7a \u0111\u1ea1i l\u01b0\u1ee3ng $x$","Hai \u0111\u1ea1i l\u01b0\u1ee3ng li\u00ean h\u1ec7 v\u1edbi nhau b\u1edfi c\u00f4ng th\u1ee9c $y = 5x $"],"explain":["Ta c\u00f3: $\\dfrac{5}{1} = \\dfrac{15}{3} = \\dfrac{25}{5} = \\dfrac{35}{7} = 5 $ <br\/> Do \u0111\u00f3 \u0111\u1ea1i l\u01b0\u1ee3ng $y$ t\u1ec9 l\u1ec7 thu\u1eadn v\u1edbi \u0111\u1ea1i l\u01b0\u1ee3ng $x$. ","<br\/>M\u1ed7i gi\u00e1 tr\u1ecb c\u1ee7a \u0111\u1ea1i l\u01b0\u1ee3ng $x$ \u0111\u1ec1u \u0111\u01b0\u1ee3c t\u01b0\u01a1ng \u1ee9ng v\u1edbi m\u1ed9t gi\u00e1 tr\u1ecb c\u1ee7a \u0111\u1ea1i l\u01b0\u1ee3ng $y$ n\u00ean \u0111\u1ea1i l\u01b0\u1ee3ng $y$ l\u00e0 h\u00e0m s\u1ed1 c\u1ee7a \u0111\u1ea1i l\u01b0\u1ee3ng $x$","<br\/>C\u00f4ng th\u1ee9c: $y = 5x $ v\u1edbi $x \\in \\{1; 3; 5; 7\\} $"]}]}],"id_ques":831},{"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":"Cho bi\u1ebft $x$ v\u00e0 $y$ l\u00e0 hai \u0111\u1ea1i l\u01b0\u1ee3ng t\u1ec9 l\u1ec7 thu\u1eadn. Khi $x = 10$ th\u00ec $y = 5 .$ Khi $x = -5$ th\u00ec gi\u00e1 tr\u1ecb c\u1ee7a $y$ l\u00e0: ","select":["A. $-10$ ","B. $-2,5$ ","C. $-3$ ","D. $-7$ "],"explain":"V\u00ec $y$ v\u00e0 $x$ t\u1ec9 l\u1ec7 thu\u1eadn v\u1edbi nhau n\u00ean $k = \\dfrac{y}{x} = \\dfrac{5}{10} = \\dfrac{1}{2} $ <br\/> Do \u0111\u00f3 hai \u0111\u1ea1i l\u01b0\u1ee3ng $y$ v\u00e0 $x$ li\u00ean h\u1ec7 v\u1edbi nhau b\u1edfi c\u00f4ng th\u1ee9c: $y = \\dfrac{1}{2}x $ <br\/> Khi $x = -5$ th\u00ec $y = \\dfrac{1}{2}.(-5) = -2,5 $ <br\/><br\/> <span class='basic_pink'>\u0110\u00e1p \u00e1n \u0111\u00fang l\u00e0 B. <\/span>","column":4}]}],"id_ques":832},{"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":"Cho bi\u1ebft hai \u0111\u1ea1i l\u01b0\u1ee3ng $x, y$ t\u1ec9 l\u1ec7 ngh\u1ecbch v\u1edbi nhau. H\u00e3y ch\u1ecdn c\u00e2u tr\u1ea3 l\u1eddi sai. ","select":["A. $xy = m$ ($m$ l\u00e0 h\u1eb1ng s\u1ed1, $m \\neq 0 $)","B. $y = \\dfrac{m}{x} $ ($m$ l\u00e0 h\u1eb1ng s\u1ed1, $m \\neq 0 $) ","C. C\u1ea3 A v\u00e0 B \u0111\u1ec1u \u0111\u00fang. ","D. C\u1ea3 A v\u00e0 B \u0111\u1ec1u sai. "],"explain":"$x$ v\u00e0 $y$ l\u00e0 hai \u0111\u1ea1i l\u01b0\u1ee3ng t\u1ec9 l\u1ec7 ngh\u1ecbch n\u00ean ch\u00fang li\u00ean h\u1ec7 v\u1edbi nhau b\u1edfi c\u00f4ng th\u1ee9c: <br\/> $y = \\dfrac{m}{x} $ hay $xy = m $ ($m$ l\u00e0 h\u1eb1ng s\u1ed1, $m \\neq 0 $) <br\/> V\u1eady c\u1ea3 A v\u00e0 B \u0111\u1ec1u \u0111\u00fang. <br\/><br\/> <span class='basic_pink'>C\u00e2u tr\u1ea3 l\u1eddi sai l\u00e0 D. <\/span>","column":2}]}],"id_ques":833},{"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":"Cho ba s\u1ed1 $x, y, z$ bi\u1ebft r\u1eb1ng ch\u00fang t\u1ec9 l\u1ec7 thu\u1eadn v\u1edbi 3; 5; 7 v\u00e0 $y - x$ = 10. T\u00ecm ba s\u1ed1 \u0111\u00f3? ","select":["A. 15; 21; 27 ","B. 15; 25; 35 ","C. 17; 27; 37 ","D. 17; 25; 35 "],"explain":" Ba s\u1ed1 $x, y, z$ t\u1ec9 l\u1ec7 thu\u1eadn v\u1edbi 3; 5; 7 n\u00ean theo t\u00ednh ch\u1ea5t v\u1ec1 t\u1ec9 l\u1ec7 thu\u1eadn ta c\u00f3: <br\/> $\\dfrac{x}{3} = \\dfrac{y}{5} = \\dfrac{z}{7} $ <br\/> Theo b\u00e0i: $y - x = 10$ <br\/> \u00c1p d\u1ee5ng t\u00ednh ch\u1ea5t d\u00e3y t\u1ec9 s\u1ed1 b\u1eb1ng nhau, ta \u0111\u01b0\u1ee3c: <br\/> $\\begin{aligned} & \\dfrac{x}{3}=\\dfrac{y}{5}=\\dfrac{z}{7}=\\dfrac{y-x}{5-3}=\\dfrac{10}{2}=5 \\\\ & \\Rightarrow \\left\\{ \\begin{aligned} & x=3.5=15 \\\\ & y=5.5=25 \\\\ & z=7.5=35 \\\\ \\end{aligned} \\right. \\\\ \\end{aligned} $ <br\/><br\/> <span class='basic_pink'>\u0110\u00e1p \u00e1n \u0111\u00fang l\u00e0 B. <\/span>","column":2}]}],"id_ques":834},{"time":24,"part":[{"title":"\u0110i\u1ec1n t\u1eeb th\u00edch h\u1ee3p v\u00e0o ch\u1ed7 tr\u1ed1ng","title_trans":"","temp":"fill_the_blank_random","correct":[[["705"],["376"],["235"]]],"list":[{"point":5,"width":20,"content":"","type_input":"","ques":"Chia s\u1ed1 1316 th\u00e0nh 3 ph\u1ea7n t\u1ec9 l\u1ec7 ngh\u1ecbch v\u1edbi $\\dfrac{2}{3}; \\dfrac{5}{4} $ v\u00e0 2. <br\/> <b> \u0110\u00e1p s\u1ed1: <\/b> $\\FormInput[40][bl_elm_true basic_elm basic_blank basic_blank_part]{}; \\FormInput[40][bl_elm_true basic_elm basic_blank basic_blank_part]{}; \\FormInput[40][bl_elm_true basic_elm basic_blank basic_blank_part]{}$","explain":" <span class='basic_left'>G\u1ecdi ba ph\u1ea7n c\u1ea7n t\u00ecm l\u00e0 x, y, z. <br\/> V\u00ec x, y, z t\u1ec9 l\u1ec7 ngh\u1ecbch v\u1edbi $\\dfrac{2}{3}; \\dfrac{5}{4}; 2 $ n\u00ean ta c\u00f3: $\\dfrac{2}{3}x = \\dfrac{5}{4}y = 2z $ <br\/> Do \u0111\u00f3: $\\begin{aligned}&\\dfrac{x}{\\dfrac{3}{2}}=\\dfrac{y}{\\dfrac{4}{5}}=\\dfrac{z}{\\dfrac{1}{2}}=\\dfrac{x+y+z}{\\dfrac{3}{2}+\\dfrac{4}{5}+\\dfrac{1}{2}}=\\dfrac{1316}{\\dfrac{14}{5}}=470 \\\\ & \\Rightarrow \\left\\{ \\begin{aligned} & x=\\dfrac{3}{2}.470=705 \\\\ & y=\\dfrac{4}{5}.470=376 \\\\ & z=\\dfrac{1}{2}.470=235 \\\\ \\end{aligned} \\right. \\\\ \\end{aligned}$ <br\/><br\/> <span class='basic_pink'>V\u1eady c\u00e1c s\u1ed1 c\u1ea7n \u0111i\u1ec1n l\u1ea7n l\u01b0\u1ee3t l\u00e0 $ 705; 376; 235 $<\/span> "}]}],"id_ques":835},{"time":24,"part":[{"title":"\u0110i\u1ec1n t\u1eeb th\u00edch h\u1ee3p v\u00e0o ch\u1ed7 tr\u1ed1ng","title_trans":"","temp":"fill_the_blank_random","correct":[[["81"],["108"],["162"]]],"list":[{"point":5,"width":20,"content":"","type_input":"","ques":"Chia s\u1ed1 351 th\u00e0nh 3 ph\u1ea7n t\u1ec9 l\u1ec7 thu\u1eadn v\u1edbi 3, 4, 6. <br\/> <b> \u0110\u00e1p s\u1ed1: <\/b> $\\FormInput[40][bl_elm_true basic_elm basic_blank basic_blank_part]{}; \\FormInput[40][bl_elm_true basic_elm basic_blank basic_blank_part]{}; \\FormInput[40][bl_elm_true basic_elm basic_blank basic_blank_part]{}$","explain":" <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: $ \\begin{aligned} & \\dfrac{x}{3}=\\dfrac{y}{4}=\\dfrac{z}{6}=\\dfrac{x+y+z}{3+4+6}=\\dfrac{351}{13}=27 \\\\ & \\\\ \\end{aligned}$ <br\/> Do \u0111\u00f3: $\\left\\{ \\begin{aligned} & x=3.27=81 \\\\ & y=4.27=108 \\\\ & z=6.27=162 \\\\ \\end{aligned} \\right.$ <br\/><br\/><span class='basic_pink'> V\u1eady c\u00e1c s\u1ed1 c\u1ea7n \u0111i\u1ec1n l\u1ea7n l\u01b0\u1ee3t l\u00e0 $ 81; 108; 162. $ <\/span>"}]}],"id_ques":836},{"time":24,"part":[{"title":"\u0110i\u1ec1n t\u1eeb th\u00edch h\u1ee3p v\u00e0o ch\u1ed7 tr\u1ed1ng","title_trans":"","temp":"fill_the_blank_random","correct":[[["12"],["15"],["14"]]],"list":[{"point":5,"width":20,"content":"","type_input":"","ques":"<span class='basic_left'>S\u1ed1 ti\u1ec1n tr\u1ea3 cho ba ng\u01b0\u1eddi \u0111\u00e1nh m\u00e1y m\u1ed9t b\u1ea3n th\u1ea3o l\u00e0 41 USD. Ng\u01b0\u1eddi th\u1ee9 nh\u1ea5t l\u00e0m vi\u1ec7c trong 16 gi\u1edd, m\u1ed7i gi\u1edd \u0111\u00e1nh \u0111\u01b0\u1ee3c 3 trang. Ng\u01b0\u1eddi th\u1ee9 hai trong 12 gi\u1edd, m\u1ed7i gi\u1edd \u0111\u00e1nh \u0111\u01b0\u1ee3c 5 trang. Ng\u01b0\u1eddi th\u1ee9 ba trong 14 gi\u1edd, m\u1ed7i gi\u1edd \u0111\u00e1nh \u0111\u01b0\u1ee3c 4 trang. H\u1ecfi m\u1ed7i ng\u01b0\u1eddi nh\u1eadn \u0111\u01b0\u1ee3c bao nhi\u00eau USD? <br\/> <b> \u0110\u00e1p s\u1ed1: <\/b> $\\FormInput[40][bl_elm_true basic_elm basic_blank basic_blank_part]{}; \\FormInput[40][bl_elm_true basic_elm basic_blank basic_blank_part]{}; \\FormInput[40][bl_elm_true basic_elm basic_blank basic_blank_part]{}$ <\/span>","explain":" <span class='basic_left'>Ng\u01b0\u1eddi th\u1ee9 nh\u1ea5t \u0111\u00e1nh \u0111\u01b0\u1ee3c s\u1ed1 trang l\u00e0: 16.3 = 48 (trang) <br\/> Ng\u01b0\u1eddi th\u1ee9 hai \u0111\u00e1nh \u0111\u01b0\u1ee3c s\u1ed1 trang l\u00e0: 12.5 = 60 (trang) <br\/> Ng\u01b0\u1eddi th\u1ee9 ba \u0111\u00e1nh \u0111\u01b0\u1ee3c s\u1ed1 trang l\u00e0: 14.4 = 56 (trang) <br\/> G\u1ecdi $x, y, z$ l\u1ea7n l\u01b0\u1ee3t l\u00e0 s\u1ed1 ti\u1ec1n t\u00ednh theo \u0111\u1ed3ng m\u00e0 ng\u01b0\u1eddi th\u1ee9 nh\u1ea5t, ng\u01b0\u1eddi th\u1ee9 hai, ng\u01b0\u1eddi th\u1ee9 ba nh\u1eadn \u0111\u01b0\u1ee3c.<br\/> Theo b\u00e0i ta c\u00f3: $\\dfrac{x}{48} = \\dfrac{y}{60} = \\dfrac{z}{56} $ v\u00e0 $x + y + z = 41 $ <br\/> \u00c1p d\u1ee5ng t\u00ednh ch\u1ea5t d\u00e3y t\u1ec9 s\u1ed1 b\u1eb1ng nhau ta \u0111\u01b0\u1ee3c: <br\/> $\\begin{aligned}& \\dfrac{x}{48}=\\dfrac{y}{60}=\\dfrac{z}{56}=\\dfrac{x+y+z}{48+60+56}=\\dfrac{41}{164}=0,25 \\\\ & \\Rightarrow \\left\\{\\begin{aligned} & x=48.0,25=12 \\\\ & y=60.0,25=15 \\\\ & z=56.0,25=14 \\\\ \\end{aligned} \\right. \\\\ \\end{aligned}$ <br\/><br\/> Suy ra m\u1ed7i ng\u01b0\u1eddi \u0111\u00e3 nh\u1eadn \u0111\u01b0\u1ee3c s\u1ed1 ti\u1ec1n l\u1ea7n l\u01b0\u1ee3t l\u00e0: 12, 15, 14 (USD) <br\/> <span class='basic_pink'> V\u1eady c\u00e1c s\u1ed1 c\u1ea7n \u0111i\u1ec1n l\u1ea7n l\u01b0\u1ee3t l\u00e0 $ 12, 15, 14 $ <\/span> "}]}],"id_ques":837},{"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'>\u0110\u1ec3 l\u00e0m xong m\u1ed9t c\u00f4ng vi\u1ec7c trong 5 gi\u1edd c\u1ea7n 12 c\u00f4ng nh\u00e2n. N\u1ebfu s\u1ed1 c\u00f4ng nh\u00e2n t\u0103ng th\u00eam 8 ng\u01b0\u1eddi th\u00ec th\u1eddi gian ho\u00e0n th\u00e0nh c\u00f4ng vi\u1ec7c gi\u1ea3m \u0111\u01b0\u1ee3c m\u1ea5y gi\u1edd? (bi\u1ebft r\u1eb1ng n\u0103ng su\u1ea5t c\u1ee7a m\u1ed7i c\u00f4ng nh\u00e2n nh\u01b0 nhau). <\/span> ","select":["A. 1 gi\u1edd ","B. 2 gi\u1edd ","C. 4 gi\u1edd ","D. 3 gi\u1edd "],"explain":"<span class='basic_left'>T\u00f3m t\u1eaft \u0111\u1ec1 b\u00e0i: <br\/> <table><tr><th>Th\u1eddi gian<\/th><th>S\u1ed1 c\u00f4ng nh\u00e2n<\/th><\/tr><tr><td>5 <\/td><td>12 <\/td><\/tr><tr><td>x ?<\/td><td>12+8<\/td><\/tr><\/table> <br\/> V\u00ec s\u1ed1 l\u01b0\u1ee3ng c\u00f4ng vi\u1ec7c kh\u00f4ng \u0111\u1ed5i n\u00ean s\u1ed1 ng\u01b0\u1eddi l\u00e0m vi\u1ec7c v\u00e0 th\u1eddi gian ho\u00e0n th\u00e0nh c\u00f4ng vi\u1ec7c l\u00e0 hai \u0111\u1ea1i l\u01b0\u1ee3ng t\u1ec9 l\u1ec7 ngh\u1ecbch. <br\/> Theo t\u00ednh ch\u1ea5t c\u1ee7a \u0111\u1ea1i l\u01b0\u1ee3ng t\u1ec9 l\u1ec7 ngh\u1ecbch ta c\u00f3: <br\/> $\\dfrac{x}{5} = \\dfrac{20}{12} \\\\ \\Rightarrow x = \\dfrac{5.12}{20} = 3 $ <br\/> V\u1eady th\u1eddi gian ho\u00e0n th\u00e0nh c\u00f4ng vi\u1ec7c gi\u1ea3m \u0111\u01b0\u1ee3c: $5 - 3 = 2$ (gi\u1edd) <br\/><br\/> <span class='basic_pink'>\u0110\u00e1p \u00e1n \u0111\u00fang l\u00e0 B. <\/span>","column":2}]}],"id_ques":838},{"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'>Ba t\u1ed5 s\u1ea3n xu\u1ea5t nh\u1eadn l\u00e0m m\u1ed9t s\u1ed1 s\u1ea3n ph\u1ea9m nh\u01b0 nhau. T\u1ed5 I l\u00e0m trong 12 gi\u1edd, t\u1ed5 II l\u00e0m trong 10 gi\u1edd, t\u1ed5 III l\u00e0m trong 8 gi\u1edd. S\u1ed1 c\u00f4ng nh\u00e2n c\u1ee7a c\u1ea3 3 t\u1ed5 l\u00e0 37 ng\u01b0\u1eddi v\u00e0 n\u0103ng su\u1ea5t lao \u0111\u1ed9ng c\u1ee7a m\u1ed7i ng\u01b0\u1eddi l\u00e0 nh\u01b0 nhau. H\u1ecfi t\u1ed5 I c\u00f3 bao nhi\u00eau c\u00f4ng nh\u00e2n? <\/span> ","select":["A. 10 ","B. 12 ","C. 13 ","D. 15 "],"explain":"<span class='basic_left'>G\u1ecdi s\u1ed1 ng\u01b0\u1eddi t\u1ed5 I, II, III l\u1ea7n l\u01b0\u1ee3t l\u00e0 $x, y, z$ (ng\u01b0\u1eddi, $x, y, z \\in N^{*} $) <br\/> Theo b\u00e0i ta c\u00f3: $x+ y + z= 37$ <br\/> N\u0103ng su\u1ea5t lao \u0111\u1ed9ng nh\u01b0 nhau n\u00ean s\u1ed1 c\u00f4ng nh\u00e2n v\u00e0 th\u1eddi gian l\u00e0m vi\u1ec7c l\u00e0 hai \u0111\u1ea1i l\u01b0\u1ee3ng t\u1ec9 l\u1ec7 ngh\u1ecbch. <br\/> Do \u0111\u00f3: $\\begin{aligned}& \\dfrac{x}{\\dfrac{1}{12}}=\\dfrac{y}{\\dfrac{1}{10}}=\\dfrac{z}{\\dfrac{1}{8}}=\\dfrac{x+y+z}{\\dfrac{1}{12}+\\dfrac{1}{10}+\\dfrac{1}{8}}=\\dfrac{37}{\\dfrac{37}{120}}=120 \\\\ & \\Rightarrow \\left\\{ \\begin{aligned}& x=\\dfrac{1}{12}.120=10 \\\\ & y=\\dfrac{1}{10}.120=12 \\\\ & z=\\dfrac{1}{8}.120=15 \\\\ \\end{aligned} \\right. \\\\ \\end{aligned}$ <br\/> V\u1eady s\u1ed1 c\u00f4ng nh\u00e2n c\u1ee7a t\u1ed5 I l\u00e0: 10 (c\u00f4ng nh\u00e2n) <br\/><br\/> <span class='basic_pink'>\u0110\u00e1p \u00e1n \u0111\u00fang l\u00e0 A. <\/span>","column":4}]}],"id_ques":839},{"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'>V\u1edbi c\u00f9ng s\u1ed1 ti\u1ec1n \u0111\u1ec3 mua 38 m\u00e9t v\u1ea3i lo\u1ea1i I c\u00f3 th\u1ec3 mua \u0111\u01b0\u1ee3c bao nhi\u00eau m\u00e9t v\u1ea3i lo\u1ea1i II, bi\u1ebft r\u1eb1ng gi\u00e1 ti\u1ec1n m\u1ed9t m\u00e9t v\u1ea3i lo\u1ea1i II ch\u1ec9 b\u1eb1ng 95 % gi\u00e1 ti\u1ec1n m\u1ed9t m\u00e9t v\u1ea3i lo\u1ea1i I? <\/span> ","select":["A. 39 m\u00e9t ","B. 40 m\u00e9t","C. 41 m\u00e9t","D. 42 m\u00e9t"],"explain":" <span class='basic_left'>T\u00f3m t\u1eaft \u0111\u1ec1 b\u00e0i: <br\/> <table><tr><th>Gi\u00e1 ti\u1ec1n 1m v\u1ea3i<\/th><th>S\u1ed1 m\u00e9t v\u1ea3i mua \u0111\u01b0\u1ee3c<\/th><\/tr><tr><td>100(%)<\/td><td>38<\/td><\/tr><tr><td>95(%)<\/td><td>x?<\/td><\/tr><\/table> <br\/> Gi\u00e1 ti\u1ec1n m\u1ed9t m\u00e9t v\u1ea3i v\u1edbi s\u1ed1 m\u00e9t v\u1ea3i mua \u0111\u01b0\u1ee3c l\u00e0 hai \u0111\u1ea1i l\u01b0\u1ee3ng t\u1ec9 l\u1ec7 ngh\u1ecbch. <br\/> Theo t\u00ednh ch\u1ea5t v\u1ec1 \u0111\u1ea1i l\u01b0\u1ee3ng t\u1ec9 l\u1ec7 ngh\u1ecbch ta c\u00f3: <br\/> $\\dfrac{100}{95} = \\dfrac{x}{38} \\\\ \\Rightarrow x = \\dfrac{100.38}{95} = 40 $ <br\/> V\u1eady v\u1edbi c\u00f9ng s\u1ed1 ti\u1ec1n \u0111\u1ec3 mua 38 m\u00e9t v\u1ea3i lo\u1ea1i I th\u00ec mua \u0111\u01b0\u1ee3c 40 m\u00e9t v\u1ea3i lo\u1ea1i II. <br\/><br\/> <span class='basic_pink'>\u0110\u00e1p \u00e1n \u0111\u00fang l\u00e0 B. <\/span>","column":2}]}],"id_ques":840},{"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":"C\u00e1c gi\u00e1 tr\u1ecb t\u01b0\u01a1ng \u1ee9ng c\u1ee7a hai \u0111\u1ea1i l\u01b0\u1ee3ng $x$ v\u00e0 $y$ \u0111\u01b0\u1ee3c cho trong b\u1ea3ng sau: <br\/> <table><tr><td>x<\/td><td>$-5$<\/td><td>0<\/td><td>3<\/td><td>4<\/td><\/tr><tr><td>y<\/td><td>7<\/td><td>2<\/td><td>1<\/td><td>||<\/td><\/tr><\/table> <br\/> \u0110\u1ea1i l\u01b0\u1ee3ng $y$ c\u00f3 ph\u1ea3i l\u00e0 h\u00e0m s\u1ed1 c\u1ee7a \u0111\u1ea1i l\u01b0\u1ee3ng $x$ kh\u00f4ng? ","select":["C\u00f3","Kh\u00f4ng "],"explain":"Ta th\u1ea5y gi\u00e1 tr\u1ecb $x = 4 $ c\u1ee7a \u0111\u1ea1i l\u01b0\u1ee3ng $x$ kh\u00f4ng \u0111\u01b0\u1ee3c t\u01b0\u01a1ng \u1ee9ng v\u1edbi m\u1ed9t gi\u00e1 tr\u1ecb n\u00e0o c\u1ee7a \u0111\u1ea1i l\u01b0\u1ee3ng $y$ <br\/> n\u00ean \u0111\u1ea1i l\u01b0\u1ee3ng $y$ kh\u00f4ng ph\u1ea3i l\u00e0 h\u00e0m s\u1ed1 c\u1ee7a \u0111\u1ea1i l\u01b0\u1ee3ng $x$ . <br\/><br\/> <span class='basic_pink'>\u0110\u00e1p \u00e1n l\u00e0 ''Kh\u00f4ng''. <\/span>","column":2}]}],"id_ques":841},{"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":[[["-5"],["3"]]],"list":[{"point":5,"width":50,"ques":"Cho h\u00e0m s\u1ed1 $y = f(x) = ax (a \\neq 0) .$ Bi\u1ebft $f(2) = -5 .$ T\u00ednh $f\\left(\\dfrac{2}{3} \\right)$<br\/><b>\u0110\u00e1p \u00e1n:<\/b> = <div class=\"frac123\"><div class=\"ts\">_input_<\/div><div class=\"ms\">_input_<\/div><\/div>","explain":"Thay $x = 2, y = -5$ v\u00e0o h\u00e0m s\u1ed1 $y = ax$, ta \u0111\u01b0\u1ee3c: <br\/> $-5 = a.2 \\Rightarrow a = \\dfrac{-5}{2} $ <br\/> H\u00e0m s\u1ed1 \u0111\u00e3 cho c\u00f3 d\u1ea1ng: $y = \\dfrac{-5}{2}x $ <br\/> V\u1eady $f\\left(\\dfrac{2}{3} \\right) = \\dfrac{-5}{2}.\\dfrac{2}{3} = \\dfrac{-5}{3}$"}]}],"id_ques":842},{"time":24,"part":[{"title":"L\u1ef1a ch\u1ecdn \u0111\u00fang hay sai","title_trans":"","temp":"true_false","correct":[["t","t","f","t"]],"list":[{"point":5,"ques":"C\u00f4ng th\u1ee9c ch\u1ee9ng t\u1ecf \u0111\u1ea1i l\u01b0\u1ee3ng $y$ l\u00e0 h\u00e0m s\u1ed1 c\u1ee7a \u0111\u1ea1i l\u01b0\u1ee3ng $x$? ","image":"","col_name":["","\u0110\u00fang","Sai"],"arr_ques":["$y - 3 = x$","$-2y = x $","$y^{2} = x $","$y = 2 $"],"explain":["$y - 3 = x \\Leftrightarrow y = x + 3 $: \u0110\u1ea1i l\u01b0\u1ee3ng $y$ l\u00e0 h\u00e0m s\u1ed1 c\u1ee7a \u0111\u1ea1i l\u01b0\u1ee3ng $x$. ","<br\/> $-2y = x \\Leftrightarrow y = \\dfrac{-1}{2}x $: \u0110\u1ea1i l\u01b0\u1ee3ng $y$ l\u00e0 h\u00e0m s\u1ed1 c\u1ee7a \u0111\u1ea1i l\u01b0\u1ee3ng $x$. ","<br\/> $y^{2} = x $: \u0110\u1ea1i l\u01b0\u1ee3ng $y$ kh\u00f4ng ph\u1ea3i l\u00e0 h\u00e0m s\u1ed1 c\u1ee7a \u0111\u1ea1i l\u01b0\u1ee3ng $x$. <br\/> Ch\u1eb3ng h\u1ea1n, \u1ee9ng v\u1edbi $x = 1$ c\u00f3 hai gi\u00e1 tr\u1ecb c\u1ee7a $y$ l\u00e0 $\\pm 1 $. ","<br\/> $y = 2 $: \u0110\u1ea1i l\u01b0\u1ee3ng $y$ l\u00e0 h\u00e0m s\u1ed1 c\u1ee7a \u0111\u1ea1i l\u01b0\u1ee3ng $x$. \u0110\u00e2y l\u00e0 h\u00e0m h\u1eb1ng. "]}]}],"id_ques":843},{"time":24,"part":[{"title":"\u0110i\u1ec1n t\u1eeb th\u00edch h\u1ee3p v\u00e0o ch\u1ed7 tr\u1ed1ng","title_trans":"","temp":"fill_the_blank","correct":[[["-2"],["-4"]]],"list":[{"point":5,"width":20,"content":"","type_input":"","ques":"M\u1ed9t h\u00e0m s\u1ed1 \u0111\u01b0\u1ee3c cho b\u1eb1ng b\u1ea3ng sau: <br\/> <table><tr><td>x<\/td><td>2<\/td><td>4<\/td><td>8<\/td><td>10<\/td><\/tr><tr><td>y = f(x)<\/td><td>$-1$<\/td><td>$-2$<\/td><td>$-3$<\/td><td>$-4$<\/td><\/tr><\/table> <br\/> Khi \u0111\u00f3 $f(4) = \\FormInput[40][bl_elm_true basic_elm basic_blank basic_blank_part]{} \\\\ f(10) = \\FormInput[40][bl_elm_true basic_elm basic_blank basic_blank_part]{} $ ","explain":"Ta c\u00f3: $f(4) = -2 \\\\ f(10) = -4 $ "}]}],"id_ques":844},{"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'>\u0110\u1ea1i l\u01b0\u1ee3ng $x$ l\u1ea5y c\u00e1c gi\u00e1 tr\u1ecb l\u00e0 c\u00e1c s\u1ed1 t\u1ef1 nhi\u00ean, \u0111\u1ea1i l\u01b0\u1ee3ng $y$ l\u1ea5y gi\u00e1 tr\u1ecb l\u00e0 s\u1ed1 d\u01b0 c\u1ee7a ph\u00e9p chia $x$ cho 3. \u0110\u1ea1i l\u01b0\u1ee3ng $y$ c\u00f3 ph\u1ea3i l\u00e0m h\u00e0m s\u1ed1 c\u1ee7a \u0111\u1ea1i l\u01b0\u1ee3ng $x$ kh\u00f4ng? <\/span>","select":["C\u00f3","Kh\u00f4ng "],"explain":"\u0110\u1ea1i l\u01b0\u1ee3ng $y$ l\u00e0 h\u00e0m s\u1ed1 c\u1ee7a \u0111\u1ea1i l\u01b0\u1ee3ng $x$ v\u00ec v\u1edbi m\u1ed7i gi\u00e1 tr\u1ecb c\u1ee7a $x$ ta lu\u00f4n x\u00e1c \u0111\u1ecbnh \u0111\u01b0\u1ee3c m\u1ed9t v\u00e0 ch\u1ec9 m\u1ed9t gi\u00e1 tr\u1ecb t\u01b0\u01a1ng \u1ee9ng c\u1ee7a $y$. <br\/><br\/> <span class='basic_pink'>\u0110\u00e1p \u00e1n l\u00e0 ''C\u00f3''. <\/span>","column":2}]}],"id_ques":845},{"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":"V\u1ebd \u0111\u01b0\u1eddng th\u1eb3ng OA \u0111i qua \u0111i\u1ec3m g\u1ed1c t\u1ecda \u0111\u1ed9 O v\u00e0 \u0111i\u1ec3m $A(-1; 4).$ Trong c\u00e1c \u0111i\u1ec3m sau, \u0111i\u1ec3m n\u00e0o kh\u00f4ng thu\u1ed9c \u0111\u01b0\u1eddng th\u1eb3ng OA? ","select":["A. $B(2; -8) $","B. $ C(-3; 10) $","C. $ D(3; -12)$ ","D. $ E(4; -16)$ "],"explain":" \u0110\u01b0\u1eddng th\u1eb3ng OA c\u00f3 c\u00f4ng th\u1ee9c $y = ax $ <br\/> \u0110\u01b0\u1eddng th\u1eb3ng \u0111i qua $A(-1; 4)$ n\u00ean: $4 = a.(-1) \\Rightarrow a = -4 $ <br\/> Ph\u01b0\u01a1ng tr\u00ecnh \u0111\u01b0\u1eddng th\u1eb3ng OA c\u00f3 d\u1ea1ng: $y = -4x $ <br\/> Ta th\u1ea5y c\u00e1c \u0111i\u1ec3m B, D, E thu\u1ed9c \u0111\u01b0\u1eddng th\u1eb3ng OA v\u00ec t\u1ecda \u0111\u1ed9 c\u00e1c \u0111i\u1ec3m th\u1ecfa m\u00e3n c\u00f4ng th\u1ee9c $y = -4x $ <br\/> \u0110i\u1ec3m kh\u00f4ng thu\u1ed9c \u0111\u01b0\u1eddng th\u1eb3ng OA l\u00e0 $C(-3; 10)$<br\/><br\/> <span class='basic_pink'> \u0110\u00e1p \u00e1n \u0111\u00fang l\u00e0 B. <\/span>","column":2}]}],"id_ques":846},{"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 h\u00e0m s\u1ed1 $y = 2x - \\dfrac{3}{4} .$ \u0110i\u1ec3m n\u00e0o sau \u0111\u00e2y thu\u1ed9c \u0111\u1ed3 th\u1ecb h\u00e0m s\u1ed1 \u0111\u00e3 cho? ","select":["A. $A\\left(1; 1\\dfrac{1}{4} \\right) $","B. $B(-1; 3)$ ","C. $C\\left(0; \\dfrac{3}{4} \\right) $","D. $D\\left(-2; \\dfrac{-17}{4} \\right) $ "],"explain":" A. Thay $x = 1 $ v\u00e0o $y = 2x - \\dfrac{3}{4} $ ta \u0111\u01b0\u1ee3c $y = 2.1 - \\dfrac{3}{4} = \\dfrac{5}{4} = 1\\dfrac{1}{4} $ <br\/> $\\Rightarrow $ \u0111i\u1ec3m $A\\left(1; 1\\dfrac{1}{4} \\right) $ thu\u1ed9c \u0111\u1ed3 th\u1ecb h\u00e0m s\u1ed1 \u0111\u00e3 cho. <br\/> C\u00e1c \u0111i\u1ec3m B, C, D c\u00f3 t\u1ecda \u0111\u1ed9 kh\u00f4ng thu\u1ed9c h\u00e0m s\u1ed1 \u0111\u00e3 cho. <br\/><br\/> <span class='basic_pink'> \u0110\u00e1p \u00e1n \u0111\u00fang l\u00e0 A. <\/span><br\/>","column":2}]}],"id_ques":847},{"time":9,"part":[{"title":"V\u1ebd \u0111\u1ed3 th\u1ecb h\u00e0m s\u1ed1.","title_trans":"","temp":"coordinates","correct":[["1,-2.5","-1,2.5"]],"list":[{"point":5,"toa_do":[["0","0",""]],"is_click":1,"name_toado_click":"A","draw_line":1,"ques":"V\u1ebd \u0111\u1ed3 th\u1ecb h\u00e0m s\u1ed1 $y = \\dfrac{-5}{2}x$ <br\/> <br\/>_inputduongthang_ <br\/> H\u00e3y click th\u00eam m\u1ed9t \u0111i\u1ec3m thu\u1ed9c \u0111\u1ed3 th\u1ecb \u0111\u1ec3 v\u1ebd \u0111\u1ed3 th\u1ecb h\u00e0m s\u1ed1.","explain":"<span class='basic_left'><span class='basic_green'>H\u01b0\u1edbng d\u1eabn:<\/span><br\/> B\u01b0\u1edbc 1. X\u00e1c \u0111\u1ecbnh m\u1ed9t \u0111i\u1ec3m A thu\u1ed9c \u0111\u1ed3 th\u1ecb (kh\u00e1c g\u1ed1c O) b\u1eb1ng c\u00e1ch cho x m\u1ed9t gi\u00e1 tr\u1ecb kh\u00e1c 0 r\u1ed3i t\u00ecm gi\u00e1 tr\u1ecb t\u01b0\u01a1ng \u1ee9ng c\u1ee7a y. <br\/> B\u01b0\u1edbc 2. V\u1ebd \u0111i\u1ec3m A(x; y) <br\/> B\u01b0\u1edbc 3. V\u1ebd \u0111\u01b0\u1eddng th\u1eb3ng OA ta \u0111\u01b0\u1ee3c \u0111\u1ed3 th\u1ecb c\u1ee7a h\u00e0m s\u1ed1 \u0111\u00e3 cho. <\/span> <span class='basic_green'>B\u00e0i gi\u1ea3i:<\/span><br\/> <br\/> Cho $y = \\dfrac{-5}{2}x ,$ v\u1edbi x = 1 th\u00ec y = -2,5 <br\/> V\u1ebd \u0111i\u1ec3m $A(1; -2,5).$ \u0110\u01b0\u1eddng th\u1eb3ng OA l\u00e0 \u0111\u1ed3 th\u1ecb c\u1ee7a h\u00e0m s\u1ed1 $y = \\dfrac{-5}{2}x$ <br\/> <center><img src='https://www.luyenthi123.com/file/luyenthi123/lop7/toan/daiso/bai18/lv2/img\/D7B18-08.png' \/><\/center> "}]}],"id_ques":848},{"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":" M\u1ed9t \u0111i\u1ec3m b\u1ea5t k\u00ec n\u1eb1m tr\u00ean tr\u1ee5c tung th\u00ec: ","select":["A. C\u00f3 ho\u00e0nh \u0111\u1ed9 b\u1eb1ng 0. ","B. C\u00f3 tung \u0111\u1ed9 v\u00e0 ho\u00e0nh \u0111\u1ed9 b\u1eb1ng 0. ","C. C\u00f3 tung \u0111\u1ed9 b\u1eb1ng 0. ","D. C\u00f3 tung \u0111\u1ed9 v\u00e0 ho\u00e0nh \u0111\u1ed9 \u0111\u1ed1i nhau. "],"explain":" M\u1ed9t \u0111i\u1ec3m b\u1ea5t k\u00ec n\u1eb1m tr\u00ean tr\u1ee5c tung th\u00ec c\u00f3 ho\u00e0nh \u0111\u1ed9 b\u1eb1ng 0. <br\/><br\/> <span class='basic_pink'> \u0110\u00e1p \u00e1n \u0111\u00fang l\u00e0 A. <\/span><br\/>","column":2}]}],"id_ques":849},{"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":" Cho h\u00e0m s\u1ed1 $y = f(x) = \\dfrac{1}{3}x^{2} -1 $ th\u00ec: ","select":["A. $f(0) = \\dfrac{-2}{3} $ ","B. $f(3) = -1 $","C. $f(-1) = \\dfrac{-2}{3} $ ","D. $f(-1) = 1$ "],"explain":" Ta c\u00f3: $y = f(x) = \\dfrac{1}{3}x^{2} - 1 $ <br\/> Do \u0111\u00f3: $f(0) = \\dfrac{1}{3}.0^{2} - 1 = -1 \\\\ f(3) = \\dfrac{1}{3}.3^{2} - 1 = 2 \\\\ f(-1) = \\dfrac{1}{3}.(-1)^{2} - 1 = \\dfrac{-2}{3} $ <br\/><br\/> <span class='basic_pink'> \u0110\u00e1p \u00e1n \u0111\u00fang l\u00e0 C. <\/span><br\/>","column":2}]}],"id_ques":850}],"lesson":{"save":0,"level":2}}