{"segment":[{"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/bai6/lv1/img\/4.jpg' \/><\/center> T\u00ecm $x$ trong t\u1ec9 l\u1ec7 th\u1ee9c sau: $ x : 6 = 4 : 3 $ ","select":["A. $x = 8 $ ","B. $x = 4,5$ ","C. $x = 2$ ","D. $x = 24$ "],"explain":" <span class='basic_left'><span class='basic_green'>H\u01b0\u1edbng d\u1eabn:<\/span><br\/> Trong t\u1ec9 l\u1ec7 th\u1ee9c $ a : b = c : d $ \u0111\u00e3 bi\u1ebft $b, c, d$ th\u00ec $a = \\dfrac{bc}{d}$ <\/span> <br\/><br\/><span class='basic_green'>B\u00e0i gi\u1ea3i:<\/span><br\/> \u00c1p d\u1ee5ng t\u00ednh ch\u1ea5t c\u1ee7a t\u1ec9 l\u1ec7 th\u1ee9c ta c\u00f3: <br\/> $ x : 6 = 4 : 3 $ $\\Rightarrow x = \\dfrac{6.4}{3} = 8 $ <br\/> V\u1eady gi\u00e1 tr\u1ecb c\u1ee7a $x$ l\u00e0 $ 8 $ <br\/> <br\/> <span class='basic_pink'> \u0110\u00e1p \u00e1n \u0111\u00fang l\u00e0 A. <\/span><\/span>","column":2}]}],"id_ques":251},{"time":24,"part":[{"title":"\u0110i\u1ec1n \u0111\u00e1p \u00e1n \u0111\u00fang v\u00e0o \u00f4 tr\u1ed1ng","title_trans":"","temp":"fill_the_blank","correct":[[["-7,5"]]],"list":[{"point":5,"width":50,"type_input":"","ques":" T\u00ecm $x$ trong t\u1ec9 l\u1ec7 th\u1ee9c: $ \\dfrac{3}{x} = \\dfrac{2}{-5} $<br\/> <b> \u0110\u00e1p s\u1ed1: <\/b> $x = $ _input_ <br\/> (Vi\u1ebft k\u1ebft qu\u1ea3 d\u01b0\u1edbi d\u1ea1ng s\u1ed1 th\u1eadp ph\u00e2n)","explain":" <span class='basic_left'><span class='basic_green'>H\u01b0\u1edbng d\u1eabn:<\/span><br\/> Trong t\u1ec9 l\u1ec7 th\u1ee9c $\\dfrac{a}{b} = \\dfrac{c}{d}$ \u0111\u00e3 bi\u1ebft $a, c, d$ th\u00ec $b = \\dfrac{ad}{c}$ <\/span> <br\/><br\/><span class='basic_green'>B\u00e0i gi\u1ea3i:<\/span><br\/> \u00c1p d\u1ee5ng t\u00ednh ch\u1ea5t c\u1ee7a t\u1ec9 l\u1ec7 th\u1ee9c ta c\u00f3: <br\/> $ \\dfrac{3}{x} = \\dfrac{2}{-5} \\Rightarrow x = \\dfrac{3.(-5)}{2} = -7,5 $ <br\/> <br\/> <span class='basic_pink'> V\u1eady gi\u00e1 tr\u1ecb c\u1ee7a $x$ l\u00e0 $ -7,5 $ <\/span><\/span>"}]}],"id_ques":252},{"time":24,"part":[{"title":"\u0110i\u1ec1n \u0111\u00e1p \u00e1n \u0111\u00fang v\u00e0o \u00f4 tr\u1ed1ng","title_trans":"","temp":"fill_the_blank","correct":[[["5,25"]]],"list":[{"point":5,"width":50,"type_input":"","ques":" T\u00ecm $x$ trong t\u1ec9 l\u1ec7 th\u1ee9c: $ \\dfrac{0,12}{3} = \\dfrac{0,21}{x}$ <br\/> <b> \u0110\u00e1p s\u1ed1: <\/b> $x = $ _input_ <br\/> (Vi\u1ebft k\u1ebft qu\u1ea3 d\u01b0\u1edbi d\u1ea1ng s\u1ed1 th\u1eadp ph\u00e2n)","explain":" <span class='basic_left'><span class='basic_green'>H\u01b0\u1edbng d\u1eabn:<\/span><br\/> Trong t\u1ec9 l\u1ec7 th\u1ee9c $\\dfrac{a}{b} = \\dfrac{c}{d}$ \u0111\u00e3 bi\u1ebft $a, b, c$ th\u00ec $d = \\dfrac{bc}{a}$ <\/span> <br\/><br\/><span class='basic_green'>B\u00e0i gi\u1ea3i:<\/span><br\/> \u00c1p d\u1ee5ng t\u00ednh ch\u1ea5t c\u1ee7a t\u1ec9 l\u1ec7 th\u1ee9c ta c\u00f3: <br\/> <br\/> $ \\dfrac{0,12}{3} = \\dfrac{0,21}{x} \\Rightarrow x = \\dfrac{3.0,21}{0,12} = 5,25 $ <br\/> <br\/> <span class='basic_pink'> V\u1eady gi\u00e1 tr\u1ecb c\u1ee7a $x$ l\u00e0 $ 5,25 $ <\/span><\/span>"}]}],"id_ques":253},{"time":24,"part":[{"title":"\u0110i\u1ec1n \u0111\u00e1p \u00e1n \u0111\u00fang v\u00e0o \u00f4 tr\u1ed1ng","title_trans":"","temp":"fill_the_blank","correct":[[["-0,39"]]],"list":[{"point":5,"width":50,"type_input":"","ques":" T\u00ecm $x$ trong t\u1ec9 l\u1ec7 th\u1ee9c: $1,8 : 1,3 = (-2,7) : 5x $ <br\/> <b> \u0110\u00e1p s\u1ed1: <\/b> $ x = $ _input_<br\/> (Vi\u1ebft k\u1ebft qu\u1ea3 d\u01b0\u1edbi d\u1ea1ng s\u1ed1 th\u1eadp ph\u00e2n) ","explain":" <span class='basic_left'><span class='basic_green'>H\u01b0\u1edbng d\u1eabn:<\/span><br\/> Trong t\u1ec9 l\u1ec7 th\u1ee9c $ a : b = c : d $ \u0111\u00e3 bi\u1ebft $a, b, c$ th\u00ec $d = \\dfrac{bc}{a}$ <\/span> <br\/><br\/><span class='basic_green'>B\u00e0i gi\u1ea3i:<\/span><br\/> \u00c1p d\u1ee5ng t\u00ednh ch\u1ea5t c\u1ee7a t\u1ec9 l\u1ec7 th\u1ee9c ta c\u00f3: <br\/> $ 1,8 : 1,3 = (-2,7) : 5x \\\\ \\Rightarrow \\dfrac{1,8}{1,3}=\\dfrac{-2,7}{5x} \\\\ \\Rightarrow 5x = \\dfrac{ 1,3 . (-2,7)}{1,8} \\\\ \\Rightarrow 5x = -1,95 \\\\ \\Rightarrow x = -1,95 : 5 = -0,39 $ <br\/> <br\/> <span class='basic_pink'> V\u1eady gi\u00e1 tr\u1ecb c\u1ee7a $x$ l\u00e0 $ -0,39 $ <\/span><\/span>"}]}],"id_ques":254},{"time":24,"part":[{"title":"\u0110i\u1ec1n \u0111\u00e1p \u00e1n \u0111\u00fang v\u00e0o \u00f4 tr\u1ed1ng","title_trans":"","temp":"fill_the_blank","correct":[[["3"],["32"]]],"list":[{"point":5,"width":50,"type_input":"","ques":" T\u00ecm $x$ trong t\u1ec9 l\u1ec7 th\u1ee9c: $ 3 : \\dfrac{9}{4} = \\dfrac{3}{4} : 6x $ <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\/> Trong t\u1ec9 l\u1ec7 th\u1ee9c $ a : b = c : d $ \u0111\u00e3 bi\u1ebft $a, b, c$ th\u00ec $d = \\dfrac{bc}{a}$ <\/span> <\/span> <br\/><br\/><span class='basic_green'>B\u00e0i gi\u1ea3i:<\/span><br\/> \u00c1p d\u1ee5ng t\u00ednh ch\u1ea5t c\u1ee7a t\u1ec9 l\u1ec7 th\u1ee9c ta c\u00f3: <br\/> $ 3 : \\dfrac{9}{4} = \\dfrac{3}{4} : 6x \\\\ \\Rightarrow 6x = \\left( \\dfrac{9}{4} . \\dfrac{3}{4}\\right) : 3 \\\\ \\Rightarrow 6x = \\dfrac{9}{16} \\\\ \\Rightarrow x = \\dfrac{9}{16} : 6 = \\dfrac{3}{32}$ <br\/> <br\/> <span class='basic_pink'> V\u1eady gi\u00e1 tr\u1ecb c\u1ee7a $x$ l\u00e0 $ \\dfrac{3}{32} $ <\/span><\/span>"}]}],"id_ques":255},{"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/bai6/lv1/img\/4.jpg' \/><\/center> $-7 : 4\\dfrac{2}{3}$ v\u00e0 $0,9 : (-0,5)$ l\u1eadp th\u00e0nh m\u1ed9t t\u1ec9 l\u1ec7 th\u1ee9c \u0111\u00fang hay sai? ","select":["A. \u0110\u00fang ","B. Sai "],"hint":" T\u00ednh t\u1eebng t\u1ec9 s\u1ed1 r\u1ed3i so s\u00e1nh.","explain":" Ta c\u00f3: $ -7 : 4\\dfrac{2}{3} = -7 : \\dfrac{14}{3} = -7 . \\dfrac{3}{14} = \\dfrac{-21}{14} = \\dfrac{-3}{2} $ <br\/> $ 0,9 : (-0,5) = \\dfrac{9}{10} : \\dfrac{-5}{10} = \\dfrac{9}{10} . \\dfrac{10}{-5} = \\dfrac{-9}{5} $ <br\/> Nh\u1eadn th\u1ea5y $-7 : 4\\dfrac{2}{3} \\neq 0,9 : (-0,5)$ <br\/> N\u00ean hai t\u1ec9 s\u1ed1 n\u00e0y kh\u00f4ng l\u1eadp th\u00e0nh m\u1ed9t t\u1ec9 l\u1ec7 th\u1ee9c <br\/> <br\/> <span class='basic_pink'> \u0110\u00e1p \u00e1n \u0111\u00fang l\u00e0 B. <\/span><\/span> ","column":2}]}],"id_ques":256},{"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/bai6/lv1/img\/4.jpg' \/><\/center> $\\dfrac{2}{5} : 4$ v\u00e0 $\\dfrac{4}{5} : 8$ l\u1eadp th\u00e0nh m\u1ed9t t\u1ec9 l\u1ec7 th\u1ee9c \u0111\u00fang hay sai? ","select":["A. \u0110\u00fang ","B. Sai "],"hint":" T\u00ednh t\u1eebng t\u1ec9 s\u1ed1 r\u1ed3i so s\u00e1nh.","explain":" Ta c\u00f3: $ \\dfrac{2}{5} : 4 = \\dfrac{2}{5} . \\dfrac{1}{4} = \\dfrac{2}{20} = \\dfrac{1}{10} $ <br\/> $\\quad \\dfrac{4}{5} : 8 = \\dfrac{4}{5} . \\dfrac{1}{8} = \\dfrac{4}{40} = \\dfrac{1}{10} $ <br\/> Nh\u1eadn th\u1ea5y $\\dfrac{2}{5} : 4$ v\u00e0 $\\dfrac{4}{5} : 8$ b\u1eb1ng nhau <br\/> N\u00ean hai t\u1ec9 s\u1ed1 n\u00e0y l\u1eadp th\u00e0nh m\u1ed9t t\u1ec9 l\u1ec7 th\u1ee9c: $\\dfrac{2}{5} : 4 = \\dfrac{4}{5} : 8$ <br\/> <br\/> <span class='basic_pink'> \u0110\u00e1p \u00e1n \u0111\u00fang l\u00e0 A. <\/span><\/span> ","column":2}]}],"id_ques":257},{"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/bai6/lv1/img\/4.jpg' \/><\/center> Cho t\u1ec9 l\u1ec7 th\u1ee9c $ \\dfrac{-3,8}{x} = \\dfrac{0,26}{0,39} $ th\u00ec gi\u00e1 tr\u1ecb c\u1ee7a x l\u00e0: ","select":["A. $ x = -57$ ","B. $ x = -5,7 $ ","C. $ x = -6 $ ","D. $ x = -3 $ "],"explain":" <span class='basic_left'><span class='basic_green'>H\u01b0\u1edbng d\u1eabn:<\/span><br\/> Trong t\u1ec9 l\u1ec7 th\u1ee9c $\\dfrac{a}{b} = \\dfrac{c}{d}$ \u0111\u00e3 bi\u1ebft $a, c, d$ th\u00ec $b = \\dfrac{ad}{c}$ <\/span> <br\/><br\/><span class='basic_green'>B\u00e0i gi\u1ea3i:<\/span><br\/> \u00c1p d\u1ee5ng t\u00ednh ch\u1ea5t c\u1ee7a t\u1ec9 l\u1ec7 th\u1ee9c ta c\u00f3: <br\/> $ \\dfrac{-3,8}{x} = \\dfrac{0,26}{0,39} $ $\\Rightarrow x = \\dfrac{(-3,8).0,39}{0,26} = -5,7 $ <br\/> V\u1eady gi\u00e1 tr\u1ecb c\u1ee7a $x$ l\u00e0 $ -5,7 $ <br\/> <br\/> <span class='basic_pink'> \u0110\u00e1p \u00e1n \u0111\u00fang l\u00e0 B. <\/span><\/span>","column":2}]}],"id_ques":258},{"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":" Thay t\u1ec9 s\u1ed1 gi\u1eefa hai s\u1ed1 h\u1eefu t\u1ec9 $\\dfrac{-3}{5} : \\dfrac{12}{25}$ th\u00e0nh t\u1ec9 s\u1ed1 gi\u1eefa hai s\u1ed1 nguy\u00ean: ","select":["A. $-10 : 3 $ ","B. $-36 : 125 $ ","C. $-22 : 17 $ ","D. $-5 : 4 $ "],"explain":" <span class='basic_left'><span class='basic_green'>H\u01b0\u1edbng d\u1eabn:<\/span><br\/> <b> Thay t\u1ec9 s\u1ed1 gi\u1eefa c\u00e1c s\u1ed1 h\u1eefu t\u1ec9 b\u1eb1ng t\u1ec9 s\u1ed1 gi\u1eefa c\u00e1c s\u1ed1 nguy\u00ean <\/b> <br\/> <i> <u> Ph\u01b0\u01a1ng ph\u00e1p gi\u1ea3i: <\/i> <\/u> <br\/> $\\bullet$ Vi\u1ebft c\u00e1c s\u1ed1 h\u1eefu t\u1ec9 d\u01b0\u1edbi d\u1ea1ng ph\u00e2n s\u1ed1.<br\/> $\\bullet$ Th\u1ef1c hi\u1ec7n ph\u00e9p chia ph\u00e2n s\u1ed1. <\/span> <br\/><br\/><span class='basic_green'>B\u00e0i gi\u1ea3i:<\/span><br\/> $ \\dfrac{-3}{5} : \\dfrac{12}{25} = \\dfrac{-3}{5} . \\dfrac{25}{12} = \\dfrac{-5}{4} $ <br\/> V\u1eady: $\\dfrac{-3}{5} : \\dfrac{12}{25} = -5 : 4 $ <br\/> <br\/> <span class='basic_pink'> \u0110\u00e1p \u00e1n \u0111\u00fang l\u00e0 D. <\/span><\/span>","column":2}]}],"id_ques":259},{"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/bai6/lv1/img\/4.jpg' \/><\/center> C\u00e1c t\u1ec9 l\u1ec7 n\u00e0o sau \u0111\u00e2y l\u1eadp th\u00e0nh m\u1ed9t t\u1ec9 l\u1ec7 th\u1ee9c? ","select":[" $42 : 12 $ v\u00e0 $72 : 24$ "," $78 : 13$ v\u00e0 $72 : 12 $ "],"hint":" T\u00ednh t\u1eebng t\u1ec9 s\u1ed1 r\u1ed3i so s\u00e1nh. ","explain":" Ta c\u00f3: $A. 42 : 12 = \\dfrac{42}{12} = \\dfrac{7}{2}$ v\u00e0 $ \\quad 72 : 24 = \\dfrac{72}{24} = 3$ <br\/> Nh\u1eadn th\u1ea5y $ 42 : 12 \\neq 72 : 24$ n\u00ean kh\u00f4ng l\u1eadp th\u00e0nh m\u1ed9t t\u1ec9 l\u1ec7 th\u1ee9c <br\/> $B. 78 : 13 = \\dfrac{78}{13} = 6$ v\u00e0 $ \\quad 72 : 12 = \\dfrac{72}{12} = 6 $ <br\/> Nh\u1eadn th\u1ea5y $ 78 : 13 $ v\u00e0 $ 72 : 12 $ b\u1eb1ng nhau n\u00ean l\u1eadp th\u00e0nh m\u1ed9t t\u1ec9 l\u1ec7 th\u1ee9c $78 : 13 = 72 : 12 $ <br\/> <br\/> <span class='basic_pink'> V\u1eady $78 : 13$ v\u00e0 $72 : 12 $ l\u1eadp th\u00e0nh m\u1ed9t t\u1ec9 l\u1ec7 th\u1ee9c <\/span><\/span> ","column":2}]}],"id_ques":260},{"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 t\u1ec9 l\u1ec7 th\u1ee9c $\\dfrac{7}{11} = \\dfrac{56}{88}.$ \u0110\u00e1p \u00e1n n\u00e0o sau \u0111\u00e2y kh\u00f4ng \u0111\u00fang? ","select":["A. $ \\dfrac{88}{11} = \\dfrac{56}{7} $ ","B. $ \\dfrac{7}{56} = \\dfrac{11}{88} $ ","C. $ \\dfrac{56}{11} = \\dfrac{88}{7} $"],"explain":" <span class='basic_left'><span class='basic_green'>H\u01b0\u1edbng d\u1eabn:<\/span> <br\/> * N\u1ebfu $ad = bc$ v\u00e0 $a, b, c, d \\neq 0$ th\u00ec ta c\u00f3 c\u00e1c t\u1ec9 l\u1ec7 th\u1ee9c: <br\/> $\\dfrac{a}{b} = \\dfrac{c}{d} \\Leftrightarrow \\dfrac{a}{c} = \\dfrac{b}{d} \\Leftrightarrow \\dfrac{d}{b} = \\dfrac{c}{a} \\Leftrightarrow \\dfrac{d}{c} = \\dfrac{b}{a}$ <\/span> <br\/> <br\/> <span class='basic_green'>B\u00e0i gi\u1ea3i:<\/span><br\/> Theo t\u00ednh ch\u1ea5t c\u1ee7a t\u1ec9 l\u1ec7 th\u1ee9c ta c\u00f3: $\\dfrac{7}{11} = \\dfrac{56}{88}$ $\\Leftrightarrow 7.88 = 11.56$ <br\/> $A.\\, \\dfrac{88}{11} = \\dfrac{56}{7} \\Leftrightarrow 7.88 = 11.56 $ (\u0111\u00fang) <br\/> $B. \\,\\dfrac{7}{56} = \\dfrac{11}{88} \\Leftrightarrow 7.88 = 11.56 $ (\u0111\u00fang) <br\/> $C.\\, \\dfrac{56}{11} = \\dfrac{88}{7} \\Leftrightarrow 56.7 = 392\\neq 88.11 = 968$ (Sai) <br\/> V\u1eady \u0111\u00e1p \u00e1n C kh\u00f4ng ch\u00ednh x\u00e1c <br\/> <span class='basic_pink'> \u0110\u00e1p \u00e1n c\u1ea7n ch\u1ecdn l\u00e0 C. <\/span><\/span> ","column":3}]}],"id_ques":261},{"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/bai6/lv1/img\/2.jpg' \/><\/center> T\u00ecm $x$ trong t\u1ec9 l\u1ec7 th\u1ee9c sau: $ \\dfrac{-2}{x} = \\dfrac{-x}{\\dfrac{8}{25}}$ ","select":["A. $ x = \\pm \\dfrac{4}{5} $ ","B. $x \\in \\varnothing $ ","C. $ x = \\dfrac{4}{5} $ ","D. $ x = \\dfrac{-4}{5} $ "],"explain":" <span class='basic_left'><span class='basic_green'>H\u01b0\u1edbng d\u1eabn:<\/span><br\/> N\u1ebfu $\\dfrac{a}{b} = \\dfrac{c}{d} \\Leftrightarrow ad = bc$ <br\/> (t\u00edch c\u00e1c ngo\u1ea1i t\u1ec9 b\u1eb1ng t\u00edch c\u00e1c trung t\u1ec9) <\/span> <br\/><br\/><span class='basic_green'>B\u00e0i gi\u1ea3i:<\/span><br\/> \u00c1p d\u1ee5ng t\u00ednh ch\u1ea5t c\u1ee7a t\u1ec9 l\u1ec7 th\u1ee9c ta c\u00f3: <br\/> $ \\dfrac{-2}{x} = \\dfrac{-x}{\\dfrac{8}{25}} $ <br\/> $\\Rightarrow -x^{2} = (-2).\\dfrac{8}{25} = \\dfrac{-16}{25} \\\\ \\Rightarrow x^{2} = \\dfrac{16}{25} \\\\ \\Rightarrow x = \\pm \\dfrac{4}{5} $ <br\/> V\u1eady gi\u00e1 tr\u1ecb c\u1ee7a $x$ l\u00e0 $ \\pm \\dfrac{4}{5} $ <br\/> <br\/> <span class='basic_pink'> \u0110\u00e1p \u00e1n \u0111\u00fang l\u00e0 A. <\/span><\/span>","column":2}]}],"id_ques":262},{"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/bai6/lv1/img\/2.jpg' \/><\/center> T\u00ecm $x$ trong t\u1ec9 l\u1ec7 th\u1ee9c sau: $ \\dfrac{x}{-15} = \\dfrac{-60}{x}$ ","select":["A. $ x = 30 $ ","B. $ x = -30 $ ","C. $ x = \\pm 30 $ ","D. $ x = 900 $ "],"explain":" <span class='basic_left'><span class='basic_green'>H\u01b0\u1edbng d\u1eabn:<\/span><br\/> N\u1ebfu $\\dfrac{a}{b} = \\dfrac{c}{d} \\Leftrightarrow ad = bc$ <br\/> (t\u00edch c\u00e1c ngo\u1ea1i t\u1ec9 b\u1eb1ng t\u00edch c\u00e1c trung t\u1ec9) <\/span> <br\/><br\/><span class='basic_green'>B\u00e0i gi\u1ea3i:<\/span><br\/> \u00c1p d\u1ee5ng t\u00ednh ch\u1ea5t c\u1ee7a t\u1ec9 l\u1ec7 th\u1ee9c ta c\u00f3: <br\/> $ \\dfrac{x}{-15} = \\dfrac{-60}{x} $ <br\/> $\\Rightarrow x^{2} = (-15).(-60) = 900 \\\\ \\Rightarrow x = \\pm 30 $ <br\/> V\u1eady gi\u00e1 tr\u1ecb c\u1ee7a x l\u00e0 $ \\pm 30 $ <br\/> <br\/> <span class='basic_pink'> \u0110\u00e1p \u00e1n \u0111\u00fang l\u00e0 C. <\/span><\/span>","column":2}]}],"id_ques":263},{"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/bai6/lv1/img\/2.jpg' \/><\/center> T\u00ecm $x$ trong t\u1ec9 l\u1ec7 th\u1ee9c: <br\/> $ \\dfrac{-0,52}{x} = \\dfrac{-9,36}{16,38}$ ","select":["A. $x = -0,91 $ ","B. $x = 0,91 $ ","C. $x = 1\\dfrac{9}{91}$ ","D. $x = -1\\dfrac{9}{91}$ "],"explain":" <span class='basic_left'><span class='basic_green'>H\u01b0\u1edbng d\u1eabn:<\/span><br\/> Trong t\u1ec9 l\u1ec7 th\u1ee9c $\\dfrac{a}{b} = \\dfrac{c}{d}$ \u0111\u00e3 bi\u1ebft $a, c, d$ th\u00ec $b = \\dfrac{ad}{c}$ <\/span> <br\/><br\/><span class='basic_green'>B\u00e0i gi\u1ea3i:<\/span><br\/> \u00c1p d\u1ee5ng t\u00ednh ch\u1ea5t c\u1ee7a t\u1ec9 l\u1ec7 th\u1ee9c ta c\u00f3: <br\/> $ \\dfrac{-0,52}{x} = \\dfrac{-9,36}{16,38} $ <br\/> $\\Rightarrow x = \\dfrac{(-0,52).16,38}{(-9,36)} = 0,91 $ <br\/> V\u1eady gi\u00e1 tr\u1ecb c\u1ee7a $x $ l\u00e0 $ 0,91 $ <br\/> <br\/> <span class='basic_pink'> \u0110\u00e1p \u00e1n \u0111\u00fang l\u00e0 B. <\/span><\/span>","column":2}]}],"id_ques":264},{"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/bai6/lv1/img\/2.jpg' \/><\/center> T\u00ecm $x$ trong t\u1ec9 l\u1ec7 th\u1ee9c $ \\dfrac{x}{27} = \\dfrac{-2}{3,6}$ ","select":["A. $x = -15$ ","B. $x = -48,6$ ","C. $x = \\dfrac{-1}{15}$ ","D. $x = \\dfrac{-4}{15}$ "],"explain":" <span class='basic_left'><span class='basic_green'>H\u01b0\u1edbng d\u1eabn:<\/span><br\/> Trong t\u1ec9 l\u1ec7 th\u1ee9c $\\dfrac{a}{b} = \\dfrac{c}{d}$ \u0111\u00e3 bi\u1ebft $b, c, d$ th\u00ec $a = \\dfrac{bc}{d}$ <\/span> <br\/><br\/><span class='basic_green'>B\u00e0i gi\u1ea3i:<\/span><br\/> \u00c1p d\u1ee5ng t\u00ednh ch\u1ea5t c\u1ee7a t\u1ec9 l\u1ec7 th\u1ee9c ta c\u00f3: <br\/> $\\dfrac{x}{27} = \\dfrac{-2}{3,6} $ <br\/> $\\Rightarrow x = \\dfrac{27.(-2)}{3,6} = -15 $ <br\/> V\u1eady gi\u00e1 tr\u1ecb c\u1ee7a $x$ l\u00e0 $ -15 $ <br\/> <br\/> <span class='basic_pink'> \u0110\u00e1p \u00e1n \u0111\u00fang l\u00e0 A. <\/span><\/span>","column":2}]}],"id_ques":265},{"time":24,"part":[{"title":"\u0110i\u1ec1n \u0111\u00e1p \u00e1n \u0111\u00fang v\u00e0o \u00f4 tr\u1ed1ng","title_trans":"","temp":"fill_the_blank","correct":[[["14"]]],"list":[{"point":5,"width":50,"type_input":"","ques":" \u0110i\u1ec1n s\u1ed1 th\u00edch h\u1ee3p v\u00e0o \u00f4 tr\u1ed1ng d\u01b0\u1edbi \u0111\u00e2y \u0111\u1ec3 c\u00f3 t\u1ec9 l\u1ec7 th\u1ee9c: <br\/> _input_: 6 = 7 : 3 ","explain":" <span class='basic_left'><span class='basic_green'>H\u01b0\u1edbng d\u1eabn:<\/span><br\/> \u00c1p d\u1ee5ng t\u00ednh ch\u1ea5t: $a : b = c : d \\Rightarrow a = bc : d $ <\/span> <br\/><br\/><span class='basic_green'>B\u00e0i gi\u1ea3i:<\/span><br\/> G\u1ecdi s\u1ed1 c\u1ea7n t\u00ecm l\u00e0 x <br\/> $ x : 6 = 7 : 3 \\\\ \\Rightarrow x = (6.7):3 = 14 $ <br\/> V\u1eady: $ 14 : 6 = 7 : 3 $ <br\/> <br\/> <span class='basic_pink'> K\u1ebft qu\u1ea3 ph\u1ea3i \u0111i\u1ec1n l\u00e0 $ 14 $ <\/span><\/span>"}]}],"id_ques":266},{"time":24,"part":[{"title":"\u0110i\u1ec1n \u0111\u00e1p \u00e1n \u0111\u00fang v\u00e0o \u00f4 tr\u1ed1ng","title_trans":"","temp":"fill_the_blank","correct":[[["-63"]]],"list":[{"point":5,"width":50,"type_input":"","ques":" \u0110i\u1ec1n s\u1ed1 th\u00edch h\u1ee3p v\u00e0o \u00f4 tr\u1ed1ng d\u01b0\u1edbi \u0111\u00e2y \u0111\u1ec3 c\u00f3 t\u1ec9 l\u1ec7 th\u1ee9c: <br\/> <br\/> (-15) : 35 = 27 : _input_","explain":" <span class='basic_left'><span class='basic_green'>H\u01b0\u1edbng d\u1eabn:<\/span><br\/> \u00c1p d\u1ee5ng t\u00ednh ch\u1ea5t: $a : b = c : d \\Rightarrow d = bc : a$ <\/span> <br\/><br\/><span class='basic_green'>B\u00e0i gi\u1ea3i:<\/span><br\/> G\u1ecdi s\u1ed1 c\u1ea7n t\u00ecm l\u00e0 x <br\/> $ (-15) : 35 = 27 : x \\\\ \\Rightarrow x = 35.27:(-15) = -63 $ <br\/> V\u1eady: $ (-15) : 35 = 27 : (-63) $ <br\/> <br\/> <span class='basic_pink'> K\u1ebft qu\u1ea3 ph\u1ea3i \u0111i\u1ec1n l\u00e0 $ -63 $ <\/span><\/span>"}]}],"id_ques":267},{"time":24,"part":[{"title":"\u0110i\u1ec1n \u0111\u00e1p \u00e1n \u0111\u00fang v\u00e0o \u00f4 tr\u1ed1ng","title_trans":"","temp":"fill_the_blank","correct":[[["44"],["15"]]],"list":[{"point":5,"width":50,"type_input":"","ques":" Thay t\u1ec9 s\u1ed1 gi\u1eefa hai s\u1ed1 h\u1eefu t\u1ec9 b\u1eb1ng t\u1ec9 s\u1ed1 gi\u1eefa hai s\u1ed1 nguy\u00ean: <br\/> <br\/> $ 2\\dfrac{1}{5} : \\dfrac{3}{4} $= _input_: _input_<br\/> (c\u00e1c s\u1ed1 h\u1ea1ng \u1edf d\u1ea1ng t\u1ed1i gi\u1ea3n) ","explain":" <span class='basic_left'><span class='basic_green'>H\u01b0\u1edbng d\u1eabn:<\/span><br\/> <b> D\u1ea1ng 1. Thay t\u1ec9 s\u1ed1 gi\u1eefa c\u00e1c s\u1ed1 h\u1eefu t\u1ec9 b\u1eb1ng t\u1ec9 s\u1ed1 gi\u1eefa c\u00e1c s\u1ed1 nguy\u00ean <\/b> <br\/> <i> <u> Ph\u01b0\u01a1ng ph\u00e1p gi\u1ea3i: <\/i> <\/u> <br\/> $\\bullet$ Vi\u1ebft c\u00e1c s\u1ed1 h\u1eefu t\u1ec9 d\u01b0\u1edbi d\u1ea1ng ph\u00e2n s\u1ed1.<br\/> $\\bullet$ Th\u1ef1c hi\u1ec7n ph\u00e9p chia ph\u00e2n s\u1ed1. <\/span> <br\/><br\/><span class='basic_green'>B\u00e0i gi\u1ea3i:<\/span><br\/> $ 2\\dfrac{1}{5} : \\dfrac{3}{4} $$ = \\dfrac{11}{5} : \\dfrac{3}{4} $$ = \\dfrac{11}{5}.\\dfrac{4}{3} = \\dfrac{44}{15}$ <br\/> V\u1eady: $ 2\\dfrac{1}{5} : \\dfrac{3}{4} = 44 : 15 $ <br\/> <br\/> <span class='basic_pink'> K\u1ebft qu\u1ea3 l\u00e0 $44 : 15 $ <\/span><\/span>"}]}],"id_ques":268},{"time":24,"part":[{"title":"\u0110i\u1ec1n \u0111\u00e1p \u00e1n \u0111\u00fang v\u00e0o \u00f4 tr\u1ed1ng","title_trans":"","temp":"fill_the_blank","correct":[[["100"],["147"]]],"list":[{"point":5,"width":50,"type_input":"","ques":" Thay t\u1ec9 s\u1ed1 gi\u1eefa hai s\u1ed1 h\u1eefu t\u1ec9 b\u1eb1ng t\u1ec9 s\u1ed1 gi\u1eefa hai s\u1ed1 nguy\u00ean: <br\/> <br\/> $ \\dfrac{2}{7} : 0,42 $ =_input_: _input_ (c\u00e1c s\u1ed1 h\u1ea1ng \u1edf d\u1ea1ng t\u1ed1i gi\u1ea3n) ","explain":" <span class='basic_left'><span class='basic_green'>H\u01b0\u1edbng d\u1eabn:<\/span><br\/> <i> <u> Ph\u01b0\u01a1ng ph\u00e1p gi\u1ea3i: <\/i> <\/u> <br\/> $\\bullet$ Vi\u1ebft c\u00e1c s\u1ed1 h\u1eefu t\u1ec9 d\u01b0\u1edbi d\u1ea1ng ph\u00e2n s\u1ed1.<br\/> $\\bullet$ Th\u1ef1c hi\u1ec7n ph\u00e9p chia ph\u00e2n s\u1ed1. <\/span> <br\/><br\/><span class='basic_green'>B\u00e0i gi\u1ea3i:<\/span><br\/> $ \\dfrac{2}{7} : 0,42 $$ = \\dfrac{2}{7} : \\dfrac{42}{100} $$ = \\dfrac{2}{7}.\\dfrac{100}{42} = \\dfrac{100}{147}$ <br\/> V\u1eady: $ \\dfrac{2}{7} : 0,42 = 100 : 147 $ <br\/> <br\/> <span class='basic_pink'> K\u1ebft qu\u1ea3 l\u00e0 $100 : 147$ <\/span><\/span>"}]}],"id_ques":269},{"time":24,"part":[{"title":"\u0110i\u1ec1n \u0111\u00e1p \u00e1n \u0111\u00fang v\u00e0o \u00f4 tr\u1ed1ng","title_trans":"","temp":"fill_the_blank","correct":[[["10"],["27"]]],"list":[{"point":5,"width":50,"type_input":"","ques":" Thay t\u1ec9 s\u1ed1 gi\u1eefa hai s\u1ed1 h\u1eefu t\u1ec9 b\u1eb1ng t\u1ec9 s\u1ed1 gi\u1eefa hai s\u1ed1 nguy\u00ean: <br\/> <br\/> 1,2 : 3,24 = _input_: _input_<br\/> (c\u00e1c s\u1ed1 h\u1ea1ng \u1edf d\u1ea1ng t\u1ed1i gi\u1ea3n) ","explain":" <span class='basic_left'><span class='basic_green'>H\u01b0\u1edbng d\u1eabn:<\/span><br\/> <i> <u> Ph\u01b0\u01a1ng ph\u00e1p gi\u1ea3i: <\/i> <\/u> <br\/> $\\bullet$ Vi\u1ebft c\u00e1c s\u1ed1 h\u1eefu t\u1ec9 d\u01b0\u1edbi d\u1ea1ng ph\u00e2n s\u1ed1.<br\/> $\\bullet$ Th\u1ef1c hi\u1ec7n ph\u00e9p chia ph\u00e2n s\u1ed1. <\/span> <br\/><br\/><span class='basic_green'>B\u00e0i gi\u1ea3i:<\/span><br\/> $1,2 : 3,24 $$ = \\dfrac{12}{10} : \\dfrac{324}{100} $$ = \\dfrac{12}{10}.\\dfrac{100}{324}$$ = \\dfrac{120}{324} = \\dfrac{10}{27} $ <br\/> V\u1eady: $1,2 : 3,24 = 10 : 27 $ <br\/> <br\/> <span class='basic_pink'> K\u1ebft qu\u1ea3 l\u00e0 $10 : 27$ <\/span><\/span>"}]}],"id_ques":270}],"lesson":{"save":0,"level":1}}