{"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/bai3/lv2/img\/2.jpg' \/><\/center> Ch\u1ecdn k\u1ebft qu\u1ea3 \u0111\u00fang c\u1ee7a ph\u00e9p to\u00e1n $ -13\\dfrac{1}{3} . \\dfrac{9}{5} $ ","select":["A. $ -6$","B. $-30$","C. $-24$","D. $-4$"],"hint":" \u00c1p d\u1ee5ng quy t\u1eafc nh\u00e2n hai s\u1ed1 h\u1eefu t\u1ec9 $\\dfrac{a}{b} . \\dfrac{c}{d} = \\dfrac{a.c}{b.d}$","explain":" Ta c\u00f3: $ -13\\dfrac{1}{3} . \\dfrac{9}{5} = \\dfrac{-40}{3} . \\dfrac{9}{5} $$= \\dfrac{(-40).9}{3.5} = \\dfrac{-360}{15} $$= -24 $ <br\/> <br\/> <span class='basic_pink'> \u0110\u00e1p \u00e1n \u0111\u00fang l\u00e0 C.<\/span><\/span> <br\/>","column":2}]}],"id_ques":121},{"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/bai3/lv2/img\/2.jpg' \/><\/center> Ch\u1ecdn k\u1ebft qu\u1ea3 \u0111\u00fang c\u1ee7a ph\u00e9p to\u00e1n $ \\dfrac{-8}{15} . \\dfrac{35}{-24} $ ","select":["A. $ \\dfrac{-7}{9}$","B. $\\dfrac{-8}{9}$","C. $\\dfrac{7}{9}$","D. $\\dfrac{8}{9}$"],"hint":" \u00c1p d\u1ee5ng quy t\u1eafc nh\u00e2n hai s\u1ed1 h\u1eefu t\u1ec9 $\\dfrac{a}{b} . \\dfrac{c}{d} = \\dfrac{a.c}{b.d}$","explain":" Ta c\u00f3: $ \\dfrac{-8}{15} . \\dfrac{35}{-24} = \\dfrac{(-8).35}{15.(-24)} = \\dfrac{(-8).5.7}{3.5.(-8).3} = \\dfrac{7}{9} $ <br\/> <br\/> <span class='basic_pink'> \u0110\u00e1p \u00e1n \u0111\u00fang l\u00e0 C.<\/span><\/span> <br\/>","column":2}]}],"id_ques":122},{"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/bai3/lv2/img\/2.jpg' \/><\/center> Ch\u1ecdn k\u1ebft qu\u1ea3 \u0111\u00fang c\u1ee7a ph\u00e9p to\u00e1n $ \\dfrac{9}{20} : (-9) $ ","select":["A. $ \\dfrac{-9}{40}$","B. $\\dfrac{-1}{20}$","C. $\\dfrac{-1}{40}$","D. $\\dfrac{1}{40}$"],"explain":" Ta c\u00f3: $ \\dfrac{9}{20} : (-9) = \\dfrac{9}{20} . \\dfrac{1}{-9}= \\dfrac{9.1}{20.(-9)} = \\dfrac{-1}{20} $ <br\/> <br\/> <span class='basic_pink'> \u0110\u00e1p \u00e1n \u0111\u00fang l\u00e0 B.<\/span><\/span> <br\/>","column":2}]}],"id_ques":123},{"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":[[["-65"],["12"]]],"list":[{"point":5,"width":50,"content":"","type_input":"","ques":" \u0110i\u1ec1n k\u1ebft qu\u1ea3 N v\u00e0o \u00f4 tr\u1ed1ng <br\/> $ N = 2\\dfrac{3}{11} . \\dfrac{13}{12} . \\dfrac{-11}{5} $ = <div class=\"frac123\"><div class=\"ts\">_input_<\/div><div class=\"ms\">_input_<\/div><\/div>","hint":" \u00c1p d\u1ee5ng quy t\u1eafc nh\u00e2n s\u1ed1 h\u1eefu t\u1ec9 $\\dfrac{a}{b} . \\dfrac{c}{d} . \\dfrac{e}{f} = \\dfrac{a.c.e}{b.d.f}$","explain":" Ta c\u00f3: $ N = 2\\dfrac{3}{11} . \\dfrac{13}{12} . \\dfrac{-11}{5} $$ = \\dfrac{25}{11} . \\dfrac{13}{12} . \\dfrac{-11}{5} $$ = \\dfrac{25.13.(-11)}{11.12.5} $$ = \\dfrac{5.13.(-1)}{1.12.1} = \\dfrac{-65}{12} $ <br\/> <br\/> <span class='basic_pink'> Gi\u00e1 tr\u1ecb c\u1ee7a N l\u00e0 $\\dfrac{-65}{12}$.<\/span><\/span> <br\/>"}]}],"id_ques":124},{"time":24,"part":[{"title":"L\u1ef1a ch\u1ecdn \u0111\u00e1p \u00e1n \u0111\u00fang nh\u1ea5t","title_trans":"","temp":"multiple_choice","correct":[[4]],"list":[{"point":5,"ques":" <center><img src='https://www.luyenthi123.com/file/luyenthi123/lop7/toan/daiso/bai3/lv2/img\/2.jpg' \/><\/center> Ch\u1ecdn k\u1ebft qu\u1ea3 \u0111\u00fang c\u1ee7a ph\u00e9p to\u00e1n $ A = \\dfrac{1}{2} + 22\\dfrac{1}{2} : \\left( \\dfrac{-3}{4} \\right)$ ","select":["A. $ \\dfrac{-63}{2}$","B. $-28\\dfrac{1}{2}$","C. $\\dfrac{-69}{2}$","D. $-29\\dfrac{1}{2}$"],"explain":" Ta c\u00f3: $ A = \\dfrac{1}{2} + 22\\dfrac{1}{2} : \\left( \\dfrac{-3}{4} \\right) $$ = \\dfrac{1}{2} + \\dfrac{45}{2} . \\dfrac{4}{-3} $$ = \\dfrac{1}{2} + \\dfrac{180}{-6} $$ = \\dfrac{1}{2} + (-30) $$ = \\dfrac{1+(-60)}{2} $$= \\dfrac{-59}{2} = -29\\dfrac{1}{2} $ <br\/> <br\/> <span class='basic_pink'> \u0110\u00e1p \u00e1n \u0111\u00fang l\u00e0 D.<\/span><\/span> <br\/>","column":2}]}],"id_ques":125},{"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/bai3/lv2/img\/4.jpg' \/><\/center>Ch\u1ecdn k\u1ebft qu\u1ea3 \u0111\u00fang c\u1ee7a ph\u00e9p to\u00e1n $ B = \\dfrac{2}{15} . \\dfrac{5}{8} - \\dfrac{5}{6} . \\dfrac{-2}{3}$ ","select":["A. $ \\dfrac{17}{36}$","B. $\\dfrac{-17}{36}$","C. $\\dfrac{-23}{36}$","D. $\\dfrac{23}{36}$"],"hint":" \u00c1p d\u1ee5ng quy t\u1eafc nh\u00e2n hai s\u1ed1 h\u1eefu t\u1ec9 $\\dfrac{a}{b} . \\dfrac{c}{d} = \\dfrac{a.c}{b.d}$","explain":" Ta c\u00f3: $ B = \\dfrac{2}{15} . \\dfrac{5}{8} - \\dfrac{5}{6} . \\dfrac{-2}{3} $$ = \\dfrac{2.5}{15.8} - \\dfrac{5.(-2)}{6.3} $$ = \\dfrac{10}{120} - \\dfrac{-10}{18} $$ = \\dfrac{1}{12} - \\dfrac{-5}{9} $$ = \\dfrac{3}{36} - \\dfrac{-20}{36} $$= \\dfrac{23}{36} $ <br\/> <br\/> <span class='basic_pink'> \u0110\u00e1p \u00e1n \u0111\u00fang l\u00e0 D.<\/span><\/span> <br\/>","column":2}]}],"id_ques":126},{"time":24,"part":[{"title":"L\u1ef1a ch\u1ecdn \u0111\u00e1p \u00e1n \u0111\u00fang nh\u1ea5t","title_trans":"","temp":"multiple_choice","correct":[[4]],"list":[{"point":5,"ques":" <center><img src='https://www.luyenthi123.com/file/luyenthi123/lop7/toan/daiso/bai3/lv2/img\/4.jpg' \/><\/center> Ch\u1ecdn k\u1ebft qu\u1ea3 \u0111\u00fang c\u1ee7a ph\u00e9p to\u00e1n $ C = \\left( \\dfrac{41}{75} + \\dfrac{17}{100} \\right) : \\dfrac{-129}{80}$ ","select":["A. $ \\dfrac{215}{300}$","B. $\\dfrac{80}{9}$","C. $\\dfrac{-215}{129}$","D. $\\dfrac{-4}{9}$"],"hint":" \u00c1p d\u1ee5ng quy t\u1eafc chia hai s\u1ed1 h\u1eefu t\u1ec9 $\\dfrac{a}{b} : \\dfrac{c}{d} = \\dfrac{a}{b} . \\dfrac{d}{c} = \\dfrac{a.d}{b.c}$","explain":" Ta c\u00f3: $ C = \\left( \\dfrac{41}{75} + \\dfrac{17}{100} \\right) : \\dfrac{-129}{80} $$ = \\left( \\dfrac{164}{300} + \\dfrac{51}{300} \\right) . \\dfrac{80}{-129} $$ = \\dfrac{215}{300} . \\dfrac{80}{-129} $$ = \\dfrac{-4}{9} $ <br\/> <br\/> <span class='basic_pink'> \u0110\u00e1p \u00e1n \u0111\u00fang l\u00e0 D.<\/span><\/span> <br\/>","column":2}]}],"id_ques":127},{"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/bai3/lv2/img\/4.jpg' \/><\/center> Ch\u1ecdn k\u1ebft qu\u1ea3 \u0111\u00fang c\u1ee7a ph\u00e9p to\u00e1n $ D = \\dfrac{1}{3} . \\left( \\dfrac{-4}{5} + \\dfrac{-6}{5} \\right) $ ","select":["A. $ \\dfrac{-1}{15}$","B. $\\dfrac{-2}{15}$","C. $\\dfrac{-2}{3}$","D. $\\dfrac{-10}{3}$"],"explain":" Ta c\u00f3: $ D = \\dfrac{1}{3} . \\left( \\dfrac{-4}{5} + \\dfrac{-6}{5} \\right) $$ = \\dfrac{1}{3} . \\dfrac{-10}{5} $$ = \\dfrac{-10}{15} = \\dfrac{-2}{3} $ <br\/> <br\/> <span class='basic_pink'> \u0110\u00e1p \u00e1n \u0111\u00fang l\u00e0 C <\/span><\/span> <br\/>","column":2}]}],"id_ques":128},{"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":[[["-2"],["7"]]],"list":[{"point":5,"width":50,"content":"","type_input":"","ques":" T\u00ednh gi\u00e1 tr\u1ecb bi\u1ec3u th\u1ee9c: <br\/> $ P = \\dfrac{1}{7}. \\dfrac{-3}{8} + \\dfrac{1}{7} . \\dfrac{-13}{8} $ = <div class=\"frac123\"><div class=\"ts\">_input_<\/div><div class=\"ms\">_input_<\/div><\/div>","hint":" T\u00ednh ch\u1ea5t ph\u00e2n ph\u1ed1i $ ab + ac = a ( b + c ) $","explain":" Ta c\u00f3: $ P = \\dfrac{1}{7}. \\dfrac{-3}{8} + \\dfrac{1}{7} . \\dfrac{-13}{8} $$ = \\dfrac{1}{7} . \\left( \\dfrac{-3}{8} + \\dfrac{-13}{8} \\right) $$ = \\dfrac{1}{7} . \\dfrac{-16}{8} $$ = \\dfrac{-16}{56} = \\dfrac{-2}{7}$ <br\/> <br\/> <span class='basic_pink'> Gi\u00e1 tr\u1ecb c\u1ee7a P l\u00e0 $\\dfrac{-2}{7}$.<\/span><\/span> <br\/>"}]}],"id_ques":129},{"time":24,"part":[{"title":"\u0110i\u1ec1n s\u1ed1 th\u00edch h\u1ee3p v\u00e0o ch\u1ed7 tr\u1ed1ng","title_trans":"","temp":"fill_the_blank","correct":[[["-4"],["5"]]],"list":[{"point":5,"width":50,"content":"","type_input":"","ques":"\u0110i\u1ec1n k\u1ebft qu\u1ea3 c\u1ee7a bi\u1ec3u th\u1ee9c Q v\u00e0o \u00f4 tr\u1ed1ng <br\/> $ Q = \\left( \\dfrac{11}{4} : \\dfrac{33}{16} \\right) . \\dfrac{-3}{5} $ = <div class=\"frac123\"><div class=\"ts\">_input_<\/div><div class=\"ms\">_input_<\/div><\/div>","hint":" \u00c1p d\u1ee5ng quy t\u1eafc nh\u00e2n, chia hai s\u1ed1 h\u1eefu t\u1ec9 $\\dfrac{a}{b} : \\dfrac{c}{d} = \\dfrac{a}{b} . \\dfrac{d}{c} = \\dfrac{a.d}{b.c}$","explain":" Ta c\u00f3: $Q = \\left( \\dfrac{11}{4} : \\dfrac{33}{16} \\right) . \\dfrac{-3}{5} $$ = \\left( \\dfrac{11}{4} . \\dfrac{16}{33} \\right) . \\dfrac{-3}{5} $$ = \\dfrac{11.16}{4.33} . \\dfrac{-3}{5} $$ = \\dfrac{4}{3} . \\dfrac{-3}{5} = \\dfrac{-4}{5}$ <br\/> <br\/> <span class='basic_pink'> Gi\u00e1 tr\u1ecb c\u1ee7a Q l\u00e0 $\\dfrac{-4}{5}$.<\/span><\/span> <br\/>"}]}],"id_ques":130},{"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":" T\u00ecm $x \\in \\mathbb{Q}$ bi\u1ebft: $ \\dfrac{3}{4} + \\dfrac{2}{5} x = \\dfrac{29}{60}$ ","select":["A. $ x = \\dfrac{-4}{15}$","B. $x = \\dfrac{-2}{5}$","C. $x = \\dfrac{-2}{3}$","D. $ x = \\dfrac{-2}{15} $"],"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\/> <br\/> $ \\dfrac{3}{4} + \\dfrac{2}{5} x = \\dfrac{29}{60} $<br\/>$ \\Rightarrow \\dfrac{2}{5} x = \\dfrac{29}{60} - \\dfrac{3}{4} $<br\/>$ \\Rightarrow \\dfrac{2}{5} x = \\dfrac{-4}{15} $<br\/> $ \\Rightarrow x = \\dfrac{-4}{15} : \\dfrac{2}{5} $<br\/> $ \\Rightarrow x = \\dfrac{-2}{3} $ <br\/> <br\/> <span class='basic_pink'> \u0110\u00e1p \u00e1n \u0111\u00fang l\u00e0 C.<\/span><\/span> <br\/>","column":2}]}],"id_ques":131},{"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":" T\u00ecm $x \\in \\mathbb{Q}$ bi\u1ebft: $ \\dfrac{2}{3} + \\dfrac{1}{3} : x = -1\\dfrac{1}{3}$ ","select":["A. $ x = \\dfrac{-1}{3}$","B. $x = \\dfrac{-1}{12}$","C. $x = \\dfrac{-1}{2}$","D. $ x = \\dfrac{-1}{6} $"],"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\/> <br\/> $ \\dfrac{2}{3} + \\dfrac{1}{3} : x = -1\\dfrac{1}{3} $ <br\/> $ \\Rightarrow \\dfrac{1}{3} : x = \\dfrac{-4}{3} - \\dfrac{2}{3} $ <br\/> $ \\Rightarrow \\dfrac{1}{3} : x = -2 $ <br\/> $ \\Rightarrow x = \\dfrac{1}{3} : -2 $ <br\/> $ \\Rightarrow x = \\dfrac{-1}{6} $ <br\/> <br\/> <span class='basic_pink'> \u0110\u00e1p \u00e1n \u0111\u00fang l\u00e0 D.<\/span><\/span> <br\/>","column":2}]}],"id_ques":132},{"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":" T\u00ecm $x \\in \\mathbb{Q}$ bi\u1ebft: $ \\dfrac{3}{2} x + \\dfrac{6}{7} = \\dfrac{10}{3}$ ","select":["A. $ x = \\dfrac{104}{63}$","B. $x = \\dfrac{63}{104}$","C. $x = \\dfrac{28}{63}$","D. $ x = \\dfrac{52}{63} $"],"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\/> <br\/> $ \\dfrac{3}{2} x + \\dfrac{6}{7} = \\dfrac{10}{3} $ <br\/> $ \\Rightarrow \\dfrac{3}{2} x = \\dfrac{10}{3} - \\dfrac{6}{7} $ <br\/> $ \\Rightarrow \\dfrac{3}{2} x = \\dfrac{52}{21} $ <br\/> $ \\Rightarrow x = \\dfrac{52}{21} : \\dfrac{3}{2} $ <br\/> $ \\Rightarrow x = \\dfrac{104}{63} $ <br\/> <br\/> <span class='basic_pink'> \u0110\u00e1p \u00e1n \u0111\u00fang l\u00e0 A.<\/span><\/span> <br\/>","column":2}]}],"id_ques":133},{"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":" T\u00ecm $x \\in \\mathbb{Q}$ bi\u1ebft: $ \\dfrac{4}{9} x - \\dfrac{1}{2} = \\dfrac{2}{7}$ ","select":["A. $ x = \\dfrac{11}{14}$","B. $x = 1\\dfrac{43}{56}$","C. $x = 7\\dfrac{1}{14}$","D. $ x = \\dfrac{3}{11} $"],"hint":" \u00c1p d\u1ee5ng quy t\u1eafc nh\u00e2n, chia s\u1ed1 h\u1eefu t\u1ec9. Quy t\u1eafc chuy\u1ec3n v\u1ebf.","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\/> <br\/> $ \\dfrac{4}{9} x - \\dfrac{1}{2} = \\dfrac{2}{7} $ <br\/> $ \\Rightarrow \\dfrac{4}{9} x = \\dfrac{2}{7} + \\dfrac{1}{2} $ <br\/> $ \\Rightarrow \\dfrac{4}{9} x = \\dfrac{11}{14} $ <br\/> $ \\Rightarrow x = \\dfrac{11}{14} : \\dfrac{4}{9} $ <br\/> $ \\Rightarrow x = \\dfrac{99}{56} = 1\\dfrac{43}{56} $ <br\/> <br\/> <span class='basic_pink'> \u0110\u00e1p \u00e1n \u0111\u00fang l\u00e0 B.<\/span><\/span> <br\/>","column":2}]}],"id_ques":134},{"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":[[["4"]]],"list":[{"point":5,"width":50,"content":"","type_input":"","ques":" T\u00ecm $x \\in \\mathbb{Q}$ bi\u1ebft: $ x . 0,25 = \\dfrac{3}{4} + 0,25 $ <br\/> <b> \u0110\u00e1p s\u1ed1: <\/b> $ x$ = _input_ ","explain":" Ta c\u00f3: $ x . 0,25 = \\dfrac{3}{4} + 0,25 $ <br\/> $ \\Rightarrow x . \\dfrac{25}{100} = \\dfrac{3}{4} + \\dfrac{25}{100} $ <br\/> $ \\Rightarrow x . \\dfrac{1}{4} = \\dfrac{3}{4} + \\dfrac{1}{4} $ <br\/> $ \\Rightarrow x . \\dfrac{1}{4} = 1 $ <br\/> $\\Rightarrow x = 1 : \\dfrac{1}{4} $ <br\/> $\\Rightarrow x = 4 $ <br\/> <br\/> <span class='basic_pink'> Gi\u00e1 tr\u1ecb c\u1ee7a x l\u00e0 $4$.<\/span><\/span> <br\/>"}]}],"id_ques":135},{"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":[[["21"],["2"]]],"list":[{"point":5,"width":50,"content":"","type_input":"","ques":" T\u00ecm $x \\in \\mathbb{Q}$ bi\u1ebft: $ \\dfrac{2}{3} + \\dfrac{7}{4} : x = \\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":" Ta c\u00f3: $ \\dfrac{2}{3} + \\dfrac{7}{4} : x = \\dfrac{5}{6} $ <br\/> $ \\Rightarrow \\dfrac{7}{4} : x = \\dfrac{5}{6} - \\dfrac{2}{3} $ <br\/> $ \\Rightarrow \\dfrac{7}{4} : x = \\dfrac{1}{6} $ <br\/> $ \\Rightarrow x = \\dfrac{7}{4} : \\dfrac{1}{6} $ <br\/> $ \\Rightarrow x = \\dfrac{42}{4} = \\dfrac{21}{2}$ <br\/> <br\/> <span class='basic_pink'> Gi\u00e1 tr\u1ecb c\u1ee7a x l\u00e0 $\\dfrac{21}{2}$.<\/span><\/span> <br\/>"}]}],"id_ques":136},{"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 c\u1ee7a $x$ th\u1ecfa m\u00e3n $\\dfrac{3}{4} + \\dfrac{1}{4} : x = \\dfrac{2}{3}$ l\u00e0 $ \\dfrac{-5}{7}$ \u0111\u00fang hay sai? ","select":[" \u0110\u00fang "," Sai "],"hint":" Thay x v\u00e0o v\u1ebf tr\u00e1i c\u1ee7a ph\u00e9p t\u00ednh r\u1ed3i so s\u00e1nh v\u1edbi v\u1ebf ph\u1ea3i. ","explain":" Thay $x = \\dfrac{-5}{7}$ v\u00e0o v\u1ebf tr\u00e1i ta \u0111\u01b0\u1ee3c: <br\/> VT = $\\dfrac{3}{4} + \\dfrac{1}{4} : \\dfrac{-5}{7} \\\\ = \\dfrac{3}{4} + \\dfrac{1}{4} . \\dfrac{7}{-5} \\\\ = \\dfrac{3}{4} + \\dfrac{-7}{20} = \\dfrac{15}{20}+ \\dfrac{-7}{20} \\\\ = \\dfrac{8}{20} = \\dfrac{2}{5} \\neq VP = \\dfrac{2}{3}$ <br\/> <br\/> <span class='basic_pink'> K\u1ebft qu\u1ea3 l\u00e0 Sai. <\/span><\/span> <br\/>","column":2}]}],"id_ques":137},{"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":" Gi\u00e1 tr\u1ecb c\u1ee7a $x$ th\u1ecfa m\u00e3n $ \\dfrac{10}{9} : x + \\dfrac{7}{12} = \\dfrac{-2}{3}$ l\u00e0 $ \\dfrac{-8}{9}$ \u0111\u00fang hay sai? ","select":[" \u0110\u00fang "," Sai "],"hint":" Thay x v\u00e0o v\u1ebf tr\u00e1i c\u1ee7a ph\u00e9p t\u00ednh r\u1ed3i so s\u00e1nh v\u1edbi v\u1ebf ph\u1ea3i. ","explain":" Thay $ x = \\dfrac{-8}{9}$ v\u00e0o v\u1ebf tr\u00e1i ta \u0111\u01b0\u1ee3c: <br\/> $\\dfrac{10}{9} : \\dfrac{-8}{9} + \\dfrac{7}{12} = \\dfrac{10}{9} . \\dfrac{9}{-8} + \\dfrac{7}{12} $$ = \\dfrac{-10}{8} + \\dfrac{7}{12} = \\dfrac{-30}{24} + \\dfrac{14}{24} $$ = \\dfrac{-16}{24} = \\dfrac{-2}{3} = VP = \\dfrac{-2}{3}$ <br\/> <br\/> <span class='basic_pink'> K\u1ebft qu\u1ea3 l\u00e0 \u0110\u00fang. <\/span><\/span> <br\/>","column":2}]}],"id_ques":138},{"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":" So s\u00e1nh hai bi\u1ec3u th\u1ee9c: <br\/> $ P = -4\\dfrac{1}{3} \\left( \\dfrac{1}{2} - \\dfrac{1}{6} \\right) $ v\u00e0 $ Q = \\dfrac{2}{3} \\left( \\dfrac{1}{3} - \\dfrac{1}{2} - \\dfrac{3}{4} \\right) $ ","select":[" A. P = Q "," B. P > Q "," C. P < Q "],"hint":" T\u00ednh l\u1ea7n l\u01b0\u1ee3t gi\u00e1 tr\u1ecb c\u1ee7a P v\u00e0 Q r\u1ed3i so s\u00e1nh. ","explain":" $ P = -4\\dfrac{1}{3} \\left( \\dfrac{1}{2} - \\dfrac{1}{6} \\right) = \\dfrac{-13}{3} \\left( \\dfrac{3}{6} - \\dfrac{1}{6} \\right) = \\dfrac{-13}{3} . \\dfrac{2}{6} = \\dfrac{-13}{9} $ <br\/> $ Q = \\dfrac{2}{3} \\left( \\dfrac{4}{12} - \\dfrac{6}{12} - \\dfrac{9}{12} \\right) = \\dfrac{2}{3} . \\left( \\dfrac{-11}{12} \\right) = \\dfrac{-11}{18} $ <br\/> <br\/> $ P = \\dfrac{-13}{9} = \\dfrac{-26}{18} < \\dfrac{-11}{18} = Q $ Suy ra P < Q <br\/> <br\/> <span class='basic_pink'> Ph\u01b0\u01a1ng \u00e1n \u0111\u00fang l\u00e0 C. <\/span><\/span> <br\/>","column":3}]}],"id_ques":139},{"time":24,"part":[{"title":"L\u1ef1a ch\u1ecdn \u0111\u00e1p \u00e1n \u0111\u00fang nh\u1ea5t","title_trans":" So s\u00e1nh","temp":"multiple_choice","correct":[[2]],"list":[{"point":5,"ques":" So s\u00e1nh hai bi\u1ec3u th\u1ee9c: <br\/> $ P = \\left( \\dfrac{-3}{4} + \\dfrac{2}{5} \\right) : \\dfrac{3}{7} $ v\u00e0 $ Q = \\left( \\dfrac{3}{5} + \\dfrac{-1}{4} \\right) : \\dfrac{-3}{7} $ ","select":[" A. P < Q "," B. P = Q "," C. P > Q "],"hint":" T\u00ednh l\u1ea7n l\u01b0\u1ee3t gi\u00e1 tr\u1ecb c\u1ee7a P v\u00e0 Q r\u1ed3i so s\u00e1nh. ","explain":" $ P = \\left( \\dfrac{-3}{4} + \\dfrac{2}{5} \\right) : \\dfrac{3}{7} = \\left( \\dfrac{-15}{20} + \\dfrac{8}{20} \\right) : \\dfrac{3}{7} = \\dfrac{-7}{20} . \\dfrac{7}{3} = \\dfrac{-49}{60} $$ $$ Q = \\left( \\dfrac{3}{5} + \\dfrac{-1}{4} \\right) : \\dfrac{-3}{7} = \\left( \\dfrac{12}{20} + \\dfrac{-5}{20} \\right) : \\dfrac{-3}{7} = \\dfrac{7}{20} . \\dfrac{7}{-3} = \\dfrac{-49}{60} $ <br\/> <br\/> So s\u00e1nh $ P = \\dfrac{-49}{60} = Q $ <br\/> <br\/> <span class='basic_pink'> Ph\u01b0\u01a1ng \u00e1n \u0111\u00fang l\u00e0 B. <\/span><\/span> <br\/>","column":3}]}],"id_ques":140}],"lesson":{"save":0,"level":2}}