Cộng, trừ số hữu tỉ

Home Lớp 7 Toán lớp 7 - Sách kết nối tri thức Cộng, trừ số hữu tỉBài tập cơ bản

{"common":{"save":0,"post_id":"953","level":1,"total":20,"point":5,"point_extra":0},"segment":[{"id":"51","post_id":"953","mon_id":"0","chapter_id":"0","question":"L\u1ef1a ch\u1ecdn \u0111\u00e1p \u00e1n \u0111\u00fang nh\u1ea5t","options":{"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='img\/10.jpg' \/><\/center> Ch\u1ecdn k\u1ebft qu\u1ea3 \u0111\u00fang c\u1ee7a ph\u00e9p to\u00e1n $\\dfrac{-3}{21} + \\dfrac{-2}{7} $ ","select":["A. $\\dfrac{-3}{7}$","B. $\\dfrac{3}{7}$","C. $\\dfrac{7}{3}$","D. $\\dfrac{-7}{3}$"],"explain":" H\u01b0\u1edbng d\u1eabn:<\/span><br\/> Quy t\u1eafc c\u1ed9ng, tr\u1eeb s\u1ed1 h\u1eefu t\u1ec9: <\/b> <br\/> \u0110\u01b0a v\u1ec1 d\u1ea1ng hai ph\u00e2n s\u1ed1 c\u00f3 c\u00f9ng m\u1eabu s\u1ed1 d\u01b0\u01a1ng r\u1ed3i \u00e1p d\u1ee5ng quy t\u1eafc c\u1ed9ng, tr\u1eeb ph\u00e2n s\u1ed1. <br\/> V\u1edbi $ x = \\dfrac{a}{m}, \\quad y = \\dfrac{b}{m} \\quad \\left( a,b,m \\in \\mathbb{Z}, m > 0 \\right), $ ta c\u00f3: <br\/> $x + y = \\dfrac{a}{m} + \\dfrac{b}{m} = \\dfrac{a+b}{m}$ <br\/> $x - y = \\dfrac{a}{m} - \\dfrac{b}{m} = \\dfrac{a-b}{m.}$ <\/span> <br\/><br\/>B\u00e0i gi\u1ea3i:<\/span><br\/>$\\dfrac{-3}{21} + \\dfrac{-2}{7} = \\dfrac{-3}{21} + \\dfrac{-6}{21} = \\dfrac{(-3)+(-6)}{21} = \\dfrac{-9}{21}= \\dfrac{-3}{7}$ <br\/> <br\/> \u0110\u00e1p \u00e1n \u0111\u00fang l\u00e0 A.<\/span><\/span> <br\/>","column":2}]}]},"correct":"","level":"1","hint":"","answer":"","type":"json","extra_type":"","time":"0","user_id":"0","test":"0","date":"2019-09-30 09:22:42"},{"id":"52","post_id":"953","mon_id":"0","chapter_id":"0","question":"L\u1ef1a ch\u1ecdn \u0111\u00e1p \u00e1n \u0111\u00fang nh\u1ea5t","options":{"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='img\/10.jpg' \/><\/center>Ch\u1ecdn k\u1ebft qu\u1ea3 \u0111\u00fang c\u1ee7a ph\u00e9p to\u00e1n $\\dfrac{-13}{15} + \\dfrac{-5}{18} $ ","select":["A. $\\dfrac{27}{90}$","B. $\\dfrac{28}{90}$","C. $\\dfrac{-103}{90}$","D. $\\dfrac{-101}{90}$"],"explain":" H\u01b0\u1edbng d\u1eabn:<\/span><br\/> Quy t\u1eafc c\u1ed9ng, tr\u1eeb s\u1ed1 h\u1eefu t\u1ec9: <\/b> <br\/> \u0110\u01b0a v\u1ec1 d\u1ea1ng hai ph\u00e2n s\u1ed1 c\u00f3 c\u00f9ng m\u1eabu s\u1ed1 d\u01b0\u01a1ng r\u1ed3i \u00e1p d\u1ee5ng quy t\u1eafc c\u1ed9ng, tr\u1eeb ph\u00e2n s\u1ed1. <br\/> V\u1edbi $ x = \\dfrac{a}{m}, \\quad y = \\dfrac{b}{m} \\quad \\left( a,b,m \\in \\mathbb{Z}, m > 0 \\right), $ ta c\u00f3: <br\/> $x + y = \\dfrac{a}{m} + \\dfrac{b}{m} = \\dfrac{a+b}{m}$ <br\/> $x - y = \\dfrac{a}{m} - \\dfrac{b}{m} = \\dfrac{a-b}{m.}$ <\/span> <br\/><br\/>B\u00e0i gi\u1ea3i:<\/span><br\/>$\\dfrac{-13}{15} + \\dfrac{-5}{18} = \\dfrac{-78}{90} + \\dfrac{-25}{90} = \\dfrac{(-78)+(-25)}{90} = \\dfrac{-103}{90}$ <br\/> <br\/> \u0110\u00e1p \u00e1n \u0111\u00fang l\u00e0 C.<\/span><\/span> <br\/>","column":2}]}]},"correct":"","level":"1","hint":"","answer":"","type":"json","extra_type":"","time":"0","user_id":"0","test":"0","date":"2019-09-30 09:22:42"},{"id":"53","post_id":"953","mon_id":"0","chapter_id":"0","question":"L\u1ef1a ch\u1ecdn \u0111\u00e1p \u00e1n \u0111\u00fang nh\u1ea5t","options":{"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='img\/10.jpg' \/><\/center>Ch\u1ecdn k\u1ebft qu\u1ea3 \u0111\u00fang c\u1ee7a ph\u00e9p to\u00e1n $\\dfrac{-2}{5} + 0,2 $ ","select":["A. $\\dfrac{-1}{5}$","B. $\\dfrac{-3}{5}$","C. $\\dfrac{1}{5}$","D. $\\dfrac{3}{5}$"],"explain":" H\u01b0\u1edbng d\u1eabn:<\/span><br\/> Quy t\u1eafc c\u1ed9ng, tr\u1eeb s\u1ed1 h\u1eefu t\u1ec9: <\/b> <br\/> \u0110\u01b0a v\u1ec1 d\u1ea1ng hai ph\u00e2n s\u1ed1 c\u00f3 c\u00f9ng m\u1eabu s\u1ed1 d\u01b0\u01a1ng r\u1ed3i \u00e1p d\u1ee5ng quy t\u1eafc c\u1ed9ng, tr\u1eeb ph\u00e2n s\u1ed1. <br\/> V\u1edbi $ x = \\dfrac{a}{m}, \\quad y = \\dfrac{b}{m} \\quad \\left( a,b,m \\in \\mathbb{Z}, m > 0 \\right), $ ta c\u00f3: <br\/> $x + y = \\dfrac{a}{m} + \\dfrac{b}{m} = \\dfrac{a+b}{m}$ <br\/> $x - y = \\dfrac{a}{m} - \\dfrac{b}{m} = \\dfrac{a-b}{m.}$ <\/span> <br\/><br\/>B\u00e0i gi\u1ea3i:<\/span><br\/> <br\/> $\\dfrac{-2}{5} + 0,2 = \\dfrac{-2}{5} + \\dfrac{2}{10}= \\dfrac{-4}{10} + \\dfrac{2}{10} = \\dfrac{(-4)+2}{10} = \\dfrac{-2}{10} = \\dfrac{-1}{5}$ <br\/> <br\/> \u0110\u00e1p \u00e1n \u0111\u00fang l\u00e0 A.<\/span><\/span> <br\/>","column":2}]}]},"correct":"","level":"1","hint":"","answer":"","type":"json","extra_type":"","time":"0","user_id":"0","test":"0","date":"2019-09-30 09:22:42"},{"id":"54","post_id":"953","mon_id":"0","chapter_id":"0","question":"L\u1ef1a ch\u1ecdn \u0111\u00e1p \u00e1n \u0111\u00fang nh\u1ea5t","options":{"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='img\/10.jpg' \/><\/center>Ch\u1ecdn k\u1ebft qu\u1ea3 \u0111\u00fang c\u1ee7a ph\u00e9p to\u00e1n $\\dfrac{3}{4} - \\dfrac{2}{3} $ ","select":["A. $\\dfrac{1}{11}$","B. $\\dfrac{1}{12}$","C. $\\dfrac{2}{12}$","D. $\\dfrac{3}{12}$"],"explain":" H\u01b0\u1edbng d\u1eabn:<\/span><br\/> Quy t\u1eafc c\u1ed9ng, tr\u1eeb s\u1ed1 h\u1eefu t\u1ec9: <\/b> <br\/> \u0110\u01b0a v\u1ec1 d\u1ea1ng hai ph\u00e2n s\u1ed1 c\u00f3 c\u00f9ng m\u1eabu s\u1ed1 d\u01b0\u01a1ng r\u1ed3i \u00e1p d\u1ee5ng quy t\u1eafc c\u1ed9ng, tr\u1eeb ph\u00e2n s\u1ed1. <br\/> V\u1edbi $ x = \\dfrac{a}{m}, \\quad y = \\dfrac{b}{m} \\quad \\left( a,b,m \\in \\mathbb{Z}, m > 0 \\right), $ ta c\u00f3: <br\/> $x + y = \\dfrac{a}{m} + \\dfrac{b}{m} = \\dfrac{a+b}{m}$ <br\/> $x - y = \\dfrac{a}{m} - \\dfrac{b}{m} = \\dfrac{a-b}{m.}$ <\/span> <br\/><br\/>B\u00e0i gi\u1ea3i:<\/span><br\/>$\\dfrac{3}{4} - \\dfrac{2}{3} = \\dfrac{9}{12} - \\dfrac{8}{12} = \\dfrac{9-8}{12} = \\dfrac{1}{12}$ <br\/><br\/> \u0110\u00e1p \u00e1n \u0111\u00fang l\u00e0 B.<\/span><\/span> <br\/>","column":2}]}]},"correct":"","level":"1","hint":"","answer":"","type":"json","extra_type":"","time":"0","user_id":"0","test":"0","date":"2019-09-30 09:22:42"},{"id":"55","post_id":"953","mon_id":"0","chapter_id":"0","question":"L\u1ef1a ch\u1ecdn \u0111\u00e1p \u00e1n \u0111\u00fang nh\u1ea5t","options":{"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='img\/10.jpg' \/><\/center>Ch\u1ecdn k\u1ebft qu\u1ea3 \u0111\u00fang c\u1ee7a ph\u00e9p to\u00e1n $\\dfrac{-2}{5} - \\dfrac{3}{11} $ ","select":["A. $\\dfrac{-7}{11}$","B. $\\dfrac{37}{55}$","C. $\\dfrac{7}{11}$","D. $\\dfrac{-37}{55}$"],"explain":" H\u01b0\u1edbng d\u1eabn:<\/span><br\/> Quy t\u1eafc c\u1ed9ng, tr\u1eeb s\u1ed1 h\u1eefu t\u1ec9: <\/b><br\/> \u0110\u01b0a v\u1ec1 d\u1ea1ng hai ph\u00e2n s\u1ed1 c\u00f3 c\u00f9ng m\u1eabu s\u1ed1 d\u01b0\u01a1ng r\u1ed3i \u00e1p d\u1ee5ng quy t\u1eafc c\u1ed9ng, tr\u1eeb ph\u00e2n s\u1ed1. <br\/> V\u1edbi $ x = \\dfrac{a}{m}, \\quad y = \\dfrac{b}{m} \\quad \\left( a,b,m \\in \\mathbb{Z}, m > 0 \\right), $ ta c\u00f3: <br\/> $x + y = \\dfrac{a}{m} + \\dfrac{b}{m} = \\dfrac{a+b}{m}$ <br\/> $x - y = \\dfrac{a}{m} - \\dfrac{b}{m} = \\dfrac{a-b}{m.}$ <\/span> <br\/><br\/>B\u00e0i gi\u1ea3i:<\/span><br\/>$\\dfrac{-2}{5} - \\dfrac{3}{11} = \\dfrac{-22}{55} - \\dfrac{15}{55} = \\dfrac{(-22)-15}{55} = \\dfrac{-37}{55}$ <br\/> <br\/> \u0110\u00e1p \u00e1n \u0111\u00fang l\u00e0 D.<\/span><\/span> <br\/>","column":2}]}]},"correct":"","level":"1","hint":"","answer":"","type":"json","extra_type":"","time":"0","user_id":"0","test":"0","date":"2019-09-30 09:22:42"},{"id":"56","post_id":"953","mon_id":"0","chapter_id":"0","question":"L\u1ef1a ch\u1ecdn \u0111\u00e1p \u00e1n \u0111\u00fang nh\u1ea5t","options":{"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='img\/10.jpg' \/><\/center>Ch\u1ecdn k\u1ebft qu\u1ea3 \u0111\u00fang c\u1ee7a ph\u00e9p to\u00e1n $ -4 - \\dfrac{4}{5} $ ","select":["A. $\\dfrac{-16}{5}$","B. $\\dfrac{-14}{5}$","C. $\\dfrac{-24}{5}$","D. $\\dfrac{-21}{5}$"],"explain":" H\u01b0\u1edbng d\u1eabn:<\/span><br\/> Quy t\u1eafc c\u1ed9ng, tr\u1eeb s\u1ed1 h\u1eefu t\u1ec9: <\/b> <br\/> \u0110\u01b0a v\u1ec1 d\u1ea1ng hai ph\u00e2n s\u1ed1 c\u00f3 c\u00f9ng m\u1eabu s\u1ed1 d\u01b0\u01a1ng r\u1ed3i \u00e1p d\u1ee5ng quy t\u1eafc c\u1ed9ng, tr\u1eeb ph\u00e2n s\u1ed1. <br\/> V\u1edbi $ x = \\dfrac{a}{m}, \\quad y = \\dfrac{b}{m} \\quad \\left( a,b,m \\in \\mathbb{Z}, m > 0 \\right), $ ta c\u00f3: <br\/> $x + y = \\dfrac{a}{m} + \\dfrac{b}{m} = \\dfrac{a+b}{m}$ <br\/> $x - y = \\dfrac{a}{m} - \\dfrac{b}{m} = \\dfrac{a-b}{m.}$ <\/span> <br\/><br\/>B\u00e0i gi\u1ea3i:<\/span><br\/>$-4 - \\dfrac{4}{5} = \\dfrac{-4}{1} - \\dfrac{4}{5} = \\dfrac{-20}{5} - \\dfrac{4}{5} = \\dfrac{(-20)-4}{5} = \\dfrac{-24}{5}$ <br\/> <br\/> \u0110\u00e1p \u00e1n \u0111\u00fang l\u00e0 C.<\/span><\/span> <br\/>","column":2}]}]},"correct":"","level":"1","hint":"","answer":"","type":"json","extra_type":"","time":"0","user_id":"0","test":"0","date":"2019-09-30 09:22:42"},{"id":"57","post_id":"953","mon_id":"0","chapter_id":"0","question":"\u0110i\u1ec1n s\u1ed1 th\u00edch h\u1ee3p v\u00e0o ch\u1ed7 tr\u1ed1ng","options":{"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":[[["-1"],["12"]]],"list":[{"point":5,"width":40,"content":"","type_input":"","ques":"<center><img src='img\/10.jpg' \/><\/center> Gi\u00e1 tr\u1ecb c\u1ee7a bi\u1ec3u th\u1ee9c: $ M = \\dfrac{-1}{21} + \\dfrac{-1}{28} $= <div class=\"frac123\"><div class=\"ts\">_input_<\/div><div class=\"ms\">_input_<\/div><\/div><br\/> (Nh\u1eadp ph\u00e2n s\u1ed1 \u1edf d\u1ea1ng t\u1ed1i gi\u1ea3n)","explain":" H\u01b0\u1edbng d\u1eabn:<\/span><br\/> Quy t\u1eafc c\u1ed9ng, tr\u1eeb s\u1ed1 h\u1eefu t\u1ec9: <\/b> <br\/> \u0110\u01b0a v\u1ec1 d\u1ea1ng hai ph\u00e2n s\u1ed1 c\u00f3 c\u00f9ng m\u1eabu s\u1ed1 d\u01b0\u01a1ng r\u1ed3i \u00e1p d\u1ee5ng quy t\u1eafc c\u1ed9ng, tr\u1eeb ph\u00e2n s\u1ed1. <br\/> V\u1edbi $ x = \\dfrac{a}{m}, \\quad y = \\dfrac{b}{m} \\quad \\left( a,b,m \\in \\mathbb{Z}, m > 0 \\right), $ ta c\u00f3: <br\/> $x + y = \\dfrac{a}{m} + \\dfrac{b}{m} = \\dfrac{a+b}{m}$ <br\/> $x - y = \\dfrac{a}{m} - \\dfrac{b}{m} = \\dfrac{a-b}{m.}$ <\/span> <br\/><br\/>B\u00e0i gi\u1ea3i:<\/span><br\/> <br\/> $\\dfrac{-1}{21} + \\dfrac{-1}{28} = \\dfrac{-4}{84} + \\dfrac{-3}{84} = \\dfrac{(-4)+(-3)}{84} = \\dfrac{-7}{84} = \\dfrac{-1}{12}$ <br\/> <br\/> K\u1ebft qu\u1ea3 ph\u00e9p t\u00ednh l\u00e0 $\\dfrac{-1}{12}.$<\/span><\/span> <br\/>"}]}]},"correct":"","level":"1","hint":"","answer":"","type":"json","extra_type":"","time":"0","user_id":"0","test":"0","date":"2019-09-30 09:22:42"},{"id":"58","post_id":"953","mon_id":"0","chapter_id":"0","question":"\u0110i\u1ec1n s\u1ed1 th\u00edch h\u1ee3p v\u00e0o ch\u1ed7 tr\u1ed1ng","options":{"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":[[["-1"],["10"]]],"list":[{"point":5,"width":40,"content":"","type_input":"","ques":"<center><img src='img\/10.jpg' \/><\/center> Gi\u00e1 tr\u1ecb c\u1ee7a bi\u1ec3u th\u1ee9c: $ K = \\dfrac{-3}{14} + \\dfrac{4}{35} $= <div class=\"frac123\"><div class=\"ts\">_input_<\/div><div class=\"ms\">_input_<\/div><\/div><br\/> (Nh\u1eadp ph\u00e2n s\u1ed1 \u1edf d\u1ea1ng t\u1ed1i gi\u1ea3n)","explain":" H\u01b0\u1edbng d\u1eabn:<\/span><br\/> Quy t\u1eafc c\u1ed9ng, tr\u1eeb s\u1ed1 h\u1eefu t\u1ec9: <\/b> <br\/> \u0110\u01b0a v\u1ec1 d\u1ea1ng hai ph\u00e2n s\u1ed1 c\u00f3 c\u00f9ng m\u1eabu s\u1ed1 d\u01b0\u01a1ng r\u1ed3i \u00e1p d\u1ee5ng quy t\u1eafc c\u1ed9ng, tr\u1eeb ph\u00e2n s\u1ed1. <br\/> V\u1edbi $ x = \\dfrac{a}{m}, \\quad y = \\dfrac{b}{m} \\quad \\left( a,b,m \\in \\mathbb{Z}, m > 0 \\right), $ ta c\u00f3: <br\/> $x + y = \\dfrac{a}{m} + \\dfrac{b}{m} = \\dfrac{a+b}{m}$ <br\/> $x - y = \\dfrac{a}{m} - \\dfrac{b}{m} = \\dfrac{a-b}{m.}$ <\/span> <br\/><br\/>B\u00e0i gi\u1ea3i:<\/span><br\/> <br\/> $\\dfrac{-3}{14} + \\dfrac{4}{35} = \\dfrac{-15}{70} + \\dfrac{8}{70} = \\dfrac{(-15)+8}{70} = \\dfrac{-7}{70} = \\dfrac{-1}{10}$ <br\/> <br\/> K\u1ebft qu\u1ea3 ph\u00e9p t\u00ednh l\u00e0 $\\dfrac{-1}{10}.$<\/span><\/span> <br\/>"}]}]},"correct":"","level":"1","hint":"","answer":"","type":"json","extra_type":"","time":"0","user_id":"0","test":"0","date":"2019-09-30 09:22:42"},{"id":"59","post_id":"953","mon_id":"0","chapter_id":"0","question":"\u0110i\u1ec1n s\u1ed1 th\u00edch h\u1ee3p v\u00e0o ch\u1ed7 tr\u1ed1ng","options":{"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":[[["-16"],["5"]]],"list":[{"point":5,"width":40,"content":"","type_input":"","ques":"<center><img src='img\/10.jpg' \/><\/center> Gi\u00e1 tr\u1ecb c\u1ee7a bi\u1ec3u th\u1ee9c: $K = -4 - \\dfrac{-4}{5}$ = <div class=\"frac123\"><div class=\"ts\">_input_<\/div><div class=\"ms\">_input_<\/div><\/div><br\/> (Nh\u1eadp ph\u00e2n s\u1ed1 \u1edf d\u1ea1ng t\u1ed1i gi\u1ea3n)","explain":" H\u01b0\u1edbng d\u1eabn:<\/span><br\/> Quy t\u1eafc c\u1ed9ng, tr\u1eeb s\u1ed1 h\u1eefu t\u1ec9: <\/b><br\/> \u0110\u01b0a v\u1ec1 d\u1ea1ng hai ph\u00e2n s\u1ed1 c\u00f3 c\u00f9ng m\u1eabu s\u1ed1 d\u01b0\u01a1ng r\u1ed3i \u00e1p d\u1ee5ng quy t\u1eafc c\u1ed9ng, tr\u1eeb ph\u00e2n s\u1ed1. <br\/> V\u1edbi $ x = \\dfrac{a}{m}, \\quad y = \\dfrac{b}{m} \\quad \\left( a,b,m \\in \\mathbb{Z}, m > 0 \\right), $ ta c\u00f3: <br\/> $x + y = \\dfrac{a}{m} + \\dfrac{b}{m} = \\dfrac{a+b}{m}$ <br\/> $x - y = \\dfrac{a}{m} - \\dfrac{b}{m} = \\dfrac{a-b}{m.}$ <\/span> <br\/><br\/>B\u00e0i gi\u1ea3i:<\/span><br\/> <br\/> $-4 - \\dfrac{-4}{5}= \\dfrac{-4}{1} - \\dfrac{-4}{5} = \\dfrac{-20}{5} - \\dfrac{-4}{5} = \\dfrac{(-20)-(-4)}{5} = \\dfrac{-16}{5}$ <br\/> <br\/> K\u1ebft qu\u1ea3 ph\u00e9p t\u00ednh l\u00e0 $\\dfrac{-16}{5}.$<\/span><\/span> <br\/>"}]}]},"correct":"","level":"1","hint":"","answer":"","type":"json","extra_type":"","time":"0","user_id":"0","test":"0","date":"2019-09-30 09:22:42"},{"id":"60","post_id":"953","mon_id":"0","chapter_id":"0","question":"\u0110i\u1ec1n s\u1ed1 th\u00edch h\u1ee3p v\u00e0o ch\u1ed7 tr\u1ed1ng","options":{"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":[[["-17"],["91"]]],"list":[{"point":5,"width":40,"content":"","type_input":"","ques":"<center><img src='img\/10.jpg' \/><\/center> Gi\u00e1 tr\u1ecb c\u1ee7a bi\u1ec3u th\u1ee9c: $ N = \\dfrac{3}{7} - \\dfrac{8}{13} $= <div class=\"frac123\"><div class=\"ts\">_input_<\/div><div class=\"ms\">_input_<\/div><\/div><br\/> (Nh\u1eadp ph\u00e2n s\u1ed1 \u1edf d\u1ea1ng t\u1ed1i gi\u1ea3n)","explain":" H\u01b0\u1edbng d\u1eabn:<\/span><br\/> Quy t\u1eafc c\u1ed9ng, tr\u1eeb s\u1ed1 h\u1eefu t\u1ec9: <\/b><br\/> \u0110\u01b0a v\u1ec1 d\u1ea1ng hai ph\u00e2n s\u1ed1 c\u00f3 c\u00f9ng m\u1eabu s\u1ed1 d\u01b0\u01a1ng r\u1ed3i \u00e1p d\u1ee5ng quy t\u1eafc c\u1ed9ng, tr\u1eeb ph\u00e2n s\u1ed1. <br\/> V\u1edbi $ x = \\dfrac{a}{m}, \\quad y = \\dfrac{b}{m} \\quad \\left( a,b,m \\in \\mathbb{Z}, m > 0 \\right), $ ta c\u00f3: <br\/> $x + y = \\dfrac{a}{m} + \\dfrac{b}{m} = \\dfrac{a+b}{m}$ <br\/> $x - y = \\dfrac{a}{m} - \\dfrac{b}{m} = \\dfrac{a-b}{m.}$ <\/span> <br\/><br\/>B\u00e0i gi\u1ea3i:<\/span><br\/> <br\/> $ \\dfrac{3}{7} - \\dfrac{8}{13} = \\dfrac{39}{91} - \\dfrac{56}{91} = \\dfrac{39-56}{91}= \\dfrac{-17}{91} $ <br\/> <br\/> K\u1ebft qu\u1ea3 ph\u00e9p t\u00ednh l\u00e0 $\\dfrac{-17}{91}.$<\/span><\/span> <br\/>"}]}]},"correct":"","level":"1","hint":"","answer":"","type":"json","extra_type":"","time":"0","user_id":"0","test":"0","date":"2019-09-30 09:22:42"},{"id":"61","post_id":"953","mon_id":"0","chapter_id":"0","question":"L\u1ef1a ch\u1ecdn \u0111\u00e1p \u00e1n \u0111\u00fang nh\u1ea5t","options":{"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":" S\u1ed1 h\u1eefu t\u1ec9 $\\dfrac{-7}{12}$ vi\u1ebft th\u00e0nh t\u1ed5ng c\u1ee7a hai s\u1ed1 h\u1eefu t\u1ec9 \u00e2m n\u00e0o d\u01b0\u1edbi \u0111\u00e2y? ","select":["A. $\\dfrac{-1}{12} + \\dfrac{-3}{4}$","B. $\\dfrac{-1}{4} + \\dfrac{-1}{3}$"],"explain":" H\u01b0\u1edbng d\u1eabn:<\/span><br\/> Quy t\u1eafc c\u1ed9ng, tr\u1eeb s\u1ed1 h\u1eefu t\u1ec9: <\/b> <br\/> \u0110\u01b0a v\u1ec1 d\u1ea1ng hai ph\u00e2n s\u1ed1 c\u00f3 c\u00f9ng m\u1eabu s\u1ed1 d\u01b0\u01a1ng r\u1ed3i \u00e1p d\u1ee5ng quy t\u1eafc c\u1ed9ng, tr\u1eeb ph\u00e2n s\u1ed1. <br\/> V\u1edbi $ x = \\dfrac{a}{m}, \\quad y = \\dfrac{b}{m} \\quad \\left( a,b,m \\in \\mathbb{Z}, m > 0 \\right), $ ta c\u00f3: <br\/> $x + y = \\dfrac{a}{m} + \\dfrac{b}{m} = \\dfrac{a+b}{m}$ <br\/> $x - y = \\dfrac{a}{m} - \\dfrac{b}{m} = \\dfrac{a-b}{m.}$ <\/span> <br\/><br\/>B\u00e0i gi\u1ea3i:<\/span><br\/>A. $\\dfrac{-1}{12} + \\dfrac{-3}{4} = \\dfrac{-1}{12} + \\dfrac{-9}{12} = \\dfrac{(-1)+(-9)}{12}= \\dfrac{-10}{12} = \\dfrac{-5}{6}$ <br\/> <br\/>B. $\\dfrac{-1}{4} + \\dfrac{-1}{3} = \\dfrac{-3}{12} + \\dfrac{-4}{12} = \\dfrac{(-3)+(-4)}{12}= \\dfrac{-7}{12}. $ <br\/><br\/> \u0110\u00e1p \u00e1n \u0111\u00fang l\u00e0 B.<\/span><\/span> <br\/>","column":2}]}]},"correct":"","level":"1","hint":"","answer":"","type":"json","extra_type":"","time":"0","user_id":"0","test":"0","date":"2019-09-30 09:22:42"},{"id":"62","post_id":"953","mon_id":"0","chapter_id":"0","question":"L\u1ef1a ch\u1ecdn \u0111\u00e1p \u00e1n \u0111\u00fang nh\u1ea5t","options":{"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":" S\u1ed1 h\u1eefu t\u1ec9 $\\dfrac{7}{9}$ vi\u1ebft th\u00e0nh hi\u1ec7u c\u1ee7a hai s\u1ed1 h\u1eefu t\u1ec9 d\u01b0\u01a1ng n\u00e0o d\u01b0\u1edbi \u0111\u00e2y? ","select":["A. $\\dfrac{4}{9} - \\dfrac{13}{18}$","B. $\\dfrac{3}{2} - \\dfrac{13}{18}$"],"explain":" H\u01b0\u1edbng d\u1eabn:<\/span><br\/> Quy t\u1eafc c\u1ed9ng, tr\u1eeb s\u1ed1 h\u1eefu t\u1ec9: <\/b><br\/> \u0110\u01b0a v\u1ec1 d\u1ea1ng hai ph\u00e2n s\u1ed1 c\u00f3 c\u00f9ng m\u1eabu s\u1ed1 d\u01b0\u01a1ng r\u1ed3i \u00e1p d\u1ee5ng quy t\u1eafc c\u1ed9ng, tr\u1eeb ph\u00e2n s\u1ed1. <br\/> V\u1edbi $ x = \\dfrac{a}{m}, \\quad y = \\dfrac{b}{m} \\quad \\left( a,b,m \\in \\mathbb{Z}, m > 0 \\right), $ ta c\u00f3: <br\/> $x + y = \\dfrac{a}{m} + \\dfrac{b}{m} = \\dfrac{a+b}{m}$ <br\/> $x - y = \\dfrac{a}{m} - \\dfrac{b}{m} = \\dfrac{a-b}{m.}$ <\/span> <br\/><br\/>B\u00e0i gi\u1ea3i:<\/span><br\/>A. $\\dfrac{4}{9} - \\dfrac{13}{18} = \\dfrac{8}{18} - \\dfrac{13}{18} = \\dfrac{8-13}{18}= \\dfrac{-5}{18}$ <br\/> <br\/> B. $\\dfrac{3}{2} - \\dfrac{13}{18} = \\dfrac{27}{18} - \\dfrac{13}{18} = \\dfrac{27-13}{18}= \\dfrac{14}{18} = \\dfrac{7}{9}. $ <br\/><br\/> \u0110\u00e1p \u00e1n \u0111\u00fang l\u00e0 B.<\/span><\/span> <br\/>","column":2}]}]},"correct":"","level":"1","hint":"","answer":"","type":"json","extra_type":"","time":"0","user_id":"0","test":"0","date":"2019-09-30 09:22:42"},{"id":"63","post_id":"953","mon_id":"0","chapter_id":"0","question":"L\u1ef1a ch\u1ecdn \u0111\u00e1p \u00e1n \u0111\u00fang nh\u1ea5t","options":{"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='img\/10.jpg' \/><\/center>Ch\u1ecdn k\u1ebft qu\u1ea3 \u0111\u00fang c\u1ee7a ph\u00e9p to\u00e1n $ M = \\dfrac{1}{5} + \\dfrac{26}{5} - \\dfrac{6}{5} $ ","select":["A. $\\dfrac{41}{5}$","B. $\\dfrac{81}{5}$","C. $\\dfrac{21}{5}$","D. $-3,8$"],"explain":" H\u01b0\u1edbng d\u1eabn:<\/span><br\/> Quy t\u1eafc c\u1ed9ng, tr\u1eeb s\u1ed1 h\u1eefu t\u1ec9: <\/b><br\/> \u0110\u01b0a v\u1ec1 d\u1ea1ng hai ph\u00e2n s\u1ed1 c\u00f3 c\u00f9ng m\u1eabu s\u1ed1 d\u01b0\u01a1ng r\u1ed3i \u00e1p d\u1ee5ng quy t\u1eafc c\u1ed9ng, tr\u1eeb ph\u00e2n s\u1ed1. <br\/> V\u1edbi $ x = \\dfrac{a}{m}, \\quad y = \\dfrac{b}{m} \\quad \\left( a,b,m \\in \\mathbb{Z}, m > 0 \\right), $ ta c\u00f3: <br\/> $x + y = \\dfrac{a}{m} + \\dfrac{b}{m} = \\dfrac{a+b}{m}$ <br\/> $x - y = \\dfrac{a}{m} - \\dfrac{b}{m} = \\dfrac{a-b}{m.}$ <\/span> <br\/><br\/>B\u00e0i gi\u1ea3i:<\/span><br\/>$M = \\dfrac{1}{5} + \\dfrac{26}{5} - \\dfrac{6}{5} $$= \\dfrac{1+26-6}{5} $$= \\dfrac{21}{5}$ <br\/><br\/> \u0110\u00e1p \u00e1n \u0111\u00fang l\u00e0 C.<\/span><\/span> <br\/>","column":2}]}]},"correct":"","level":"1","hint":"","answer":"","type":"json","extra_type":"","time":"0","user_id":"0","test":"0","date":"2019-09-30 09:22:42"},{"id":"64","post_id":"953","mon_id":"0","chapter_id":"0","question":"L\u1ef1a ch\u1ecdn \u0111\u00e1p \u00e1n \u0111\u00fang nh\u1ea5t","options":{"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='img\/10.jpg' \/><\/center>Ch\u1ecdn k\u1ebft qu\u1ea3 \u0111\u00fang c\u1ee7a ph\u00e9p to\u00e1n $ M = \\dfrac{2}{3} + \\dfrac{-4}{3} - \\dfrac{5}{3} $ ","select":["A. $\\dfrac{-7}{3}$","B. $-2$","C. $\\dfrac{7}{3}$","D. $\\dfrac{1}{6}$"],"explain":" H\u01b0\u1edbng d\u1eabn:<\/span><br\/> Quy t\u1eafc c\u1ed9ng, tr\u1eeb s\u1ed1 h\u1eefu t\u1ec9: <\/b> <br\/> \u0110\u01b0a v\u1ec1 d\u1ea1ng hai ph\u00e2n s\u1ed1 c\u00f3 c\u00f9ng m\u1eabu s\u1ed1 d\u01b0\u01a1ng r\u1ed3i \u00e1p d\u1ee5ng quy t\u1eafc c\u1ed9ng, tr\u1eeb ph\u00e2n s\u1ed1. <br\/> V\u1edbi $ x = \\dfrac{a}{m}, \\quad y = \\dfrac{b}{m} \\quad \\left( a,b,m \\in \\mathbb{Z}, m > 0 \\right), $ ta c\u00f3: <br\/> $x + y = \\dfrac{a}{m} + \\dfrac{b}{m} = \\dfrac{a+b}{m}$ <br\/> $x - y = \\dfrac{a}{m} - \\dfrac{b}{m} = \\dfrac{a-b}{m.}$ <\/span> <br\/><br\/>B\u00e0i gi\u1ea3i:<\/span><br\/>$M = \\dfrac{2}{3} + \\dfrac{-4}{3} - \\dfrac{5}{3} $$= \\dfrac{2+(-4)-5}{3} $$= \\dfrac{-7}{3}$ <br\/><br\/> \u0110\u00e1p \u00e1n \u0111\u00fang l\u00e0 A.<\/span><\/span> <br\/>","column":2}]}]},"correct":"","level":"1","hint":"","answer":"","type":"json","extra_type":"","time":"0","user_id":"0","test":"0","date":"2019-09-30 09:22:42"},{"id":"65","post_id":"953","mon_id":"0","chapter_id":"0","question":"L\u1ef1a ch\u1ecdn \u0111\u00e1p \u00e1n \u0111\u00fang nh\u1ea5t","options":{"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='img\/10.jpg' \/><\/center>Ch\u1ecdn k\u1ebft qu\u1ea3 \u0111\u00fang c\u1ee7a ph\u00e9p to\u00e1n $ M = \\dfrac{3}{5} + \\dfrac{-4}{3} + \\dfrac{-3}{4} $ ","select":["A. $1\\dfrac{29}{60}$","B. $\\dfrac{-89}{60}$","C. $\\dfrac{10}{12}$","D. $\\dfrac{88}{60}$"],"explain":" H\u01b0\u1edbng d\u1eabn:<\/span><br\/> Quy t\u1eafc c\u1ed9ng, tr\u1eeb s\u1ed1 h\u1eefu t\u1ec9: <\/b> <br\/> \u0110\u01b0a v\u1ec1 d\u1ea1ng hai ph\u00e2n s\u1ed1 c\u00f3 c\u00f9ng m\u1eabu s\u1ed1 d\u01b0\u01a1ng r\u1ed3i \u00e1p d\u1ee5ng quy t\u1eafc c\u1ed9ng, tr\u1eeb ph\u00e2n s\u1ed1. <br\/> V\u1edbi $ x = \\dfrac{a}{m}, \\quad y = \\dfrac{b}{m} \\quad \\left( a,b,m \\in \\mathbb{Z}, m > 0 \\right), $ ta c\u00f3: <br\/> $x + y = \\dfrac{a}{m} + \\dfrac{b}{m} = \\dfrac{a+b}{m}$ <br\/> $x - y = \\dfrac{a}{m} - \\dfrac{b}{m} = \\dfrac{a-b}{m.}$ <\/span> <br\/><br\/>B\u00e0i gi\u1ea3i:<\/span><br\/>$M = \\dfrac{3}{5} + \\dfrac{-4}{3} + \\dfrac{-3}{4} $$ = \\dfrac{36}{60} + \\dfrac{-80}{60} + \\dfrac{-45}{60} $$ = \\dfrac{36+(-80)+(-45)}{60} $$ = \\dfrac{-89}{60} = -1\\dfrac{29}{60}$ <br\/> <br\/> \u0110\u00e1p \u00e1n \u0111\u00fang l\u00e0 B.<\/span><\/span> <br\/>","column":2}]}]},"correct":"","level":"1","hint":"","answer":"","type":"json","extra_type":"","time":"0","user_id":"0","test":"0","date":"2019-09-30 09:22:42"},{"id":"66","post_id":"953","mon_id":"0","chapter_id":"0","question":"L\u1ef1a ch\u1ecdn \u0111\u00e1p \u00e1n \u0111\u00fang nh\u1ea5t","options":{"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='img\/2.jpg' \/><\/center>T\u00ecm $x \\in \\mathbb{Q}$ bi\u1ebft: $\\dfrac{1}{4} + x = \\dfrac{-3}{4}. $ ","select":["A. $x = 1$","B. $x = -1$","C. $x = \\dfrac{-1}{2}$","D. $x = \\dfrac{1}{2}$"],"explain":" H\u01b0\u1edbng d\u1eabn:<\/span><br\/> 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\/>B\u00e0i gi\u1ea3i:<\/span><br\/> $\\dfrac{1}{4} + x = \\dfrac{-3}{4} \\\\ \\Rightarrow x = \\dfrac{-3}{4} - \\dfrac{1}{4} \\\\ \\Rightarrow x = \\dfrac{(-3)-1}{4}\\\\ \\Rightarrow x = \\dfrac{-4}{4} \\\\ \\Rightarrow x = -1 $ <br\/><br\/> \u0110\u00e1p \u00e1n \u0111\u00fang l\u00e0 B.<\/span><\/span> <br\/>","column":2}]}]},"correct":"","level":"1","hint":"","answer":"","type":"json","extra_type":"","time":"0","user_id":"0","test":"0","date":"2019-09-30 09:22:42"},{"id":"67","post_id":"953","mon_id":"0","chapter_id":"0","question":"L\u1ef1a ch\u1ecdn \u0111\u00e1p \u00e1n \u0111\u00fang nh\u1ea5t","options":{"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='img\/2.jpg' \/><\/center> T\u00ecm $x \\in \\mathbb{Q}$ bi\u1ebft: $\\dfrac{3}{4} - x = \\dfrac{1}{3}. $ ","select":["A. $x = \\dfrac{-5}{12}$","B. $x = \\dfrac{5}{12}$","C. $x = -2$","D. $x = 2$"],"explain":" H\u01b0\u1edbng d\u1eabn:<\/span><br\/> 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> B\u00e0i gi\u1ea3i:<\/span><br\/> $\\dfrac{3}{4} - x = \\dfrac{1}{3} \\\\ \\Rightarrow \\dfrac{3}{4} - \\dfrac{1}{3} = x \\\\ \\Rightarrow x = \\dfrac{9}{12} - \\dfrac{4}{12} = \\dfrac{5}{12}$ <br\/><br\/> \u0110\u00e1p \u00e1n \u0111\u00fang l\u00e0 B.<\/span><\/span> <br\/>","column":2}]}]},"correct":"","level":"1","hint":"","answer":"","type":"json","extra_type":"","time":"0","user_id":"0","test":"0","date":"2019-09-30 09:22:42"},{"id":"68","post_id":"953","mon_id":"0","chapter_id":"0","question":"L\u1ef1a ch\u1ecdn \u0111\u00e1p \u00e1n \u0111\u00fang nh\u1ea5t","options":{"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='img\/2.jpg' \/><\/center> T\u00ecm $x \\in \\mathbb{Q}$ bi\u1ebft: $ x + \\dfrac{1}{3} = \\dfrac{-3}{4}. $ ","select":["A. $\\dfrac{13}{12}$","B. $\\dfrac{-13}{12}$","C. $\\dfrac{5}{6}$","D. $\\dfrac{4}{6}$"],"explain":" H\u01b0\u1edbng d\u1eabn:<\/span><br\/> 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. <br\/> B\u00e0i gi\u1ea3i:<\/span><br\/> $x + \\dfrac{1}{3} = \\dfrac{-3}{4} \\\\ \\Rightarrow x = \\dfrac{-3}{4} - \\dfrac{1}{3} \\\\ \\Rightarrow x = \\dfrac{-13}{12}$ <br\/> <br\/> \u0110\u00e1p \u00e1n \u0111\u00fang l\u00e0 B.<\/span><\/span> <br\/>","column":2}]}]},"correct":"","level":"1","hint":"","answer":"","type":"json","extra_type":"","time":"0","user_id":"0","test":"0","date":"2019-09-30 09:22:42"},{"id":"69","post_id":"953","mon_id":"0","chapter_id":"0","question":"\u0110i\u1ec1n \u0111\u00e1p \u00e1n \u0111\u00fang v\u00e0o ch\u1ed7 tr\u1ed1ng","options":{"time":24,"part":[{"title":"\u0110i\u1ec1n \u0111\u00e1p \u00e1n \u0111\u00fang v\u00e0o ch\u1ed7 tr\u1ed1ng","title_trans":"","temp":"fill_the_blank","correct":[[["31"],["6"]]],"list":[{"point":5,"width":40,"content":"","type_input":"","ques":"<center><img src='img\/10.jpg' \/><\/center> \u0110i\u1ec1n k\u1ebft qu\u1ea3 \u0111\u00fang v\u00e0o \u00f4 tr\u1ed1ng $ 5 + \\dfrac{5}{3} - \\dfrac{3}{2} $= <div class=\"frac123\"><div class=\"ts\">_input_<\/div><div class=\"ms\">_input_<\/div><\/div> (Nh\u1eadp ph\u00e2n s\u1ed1 \u1edf d\u1ea1ng t\u1ed1i gi\u1ea3n)","explain":" H\u01b0\u1edbng d\u1eabn:<\/span><br\/> Quy t\u1eafc c\u1ed9ng, tr\u1eeb s\u1ed1 h\u1eefu t\u1ec9: <\/b> <br\/> \u0110\u01b0a v\u1ec1 d\u1ea1ng hai ph\u00e2n s\u1ed1 c\u00f3 c\u00f9ng m\u1eabu s\u1ed1 d\u01b0\u01a1ng r\u1ed3i \u00e1p d\u1ee5ng quy t\u1eafc c\u1ed9ng, tr\u1eeb ph\u00e2n s\u1ed1. <br\/> V\u1edbi $ x = \\dfrac{a}{m}, \\quad y = \\dfrac{b}{m} \\quad \\left( a,b,m \\in \\mathbb{Z}, m > 0 \\right), $ ta c\u00f3: <br\/> $x + y = \\dfrac{a}{m} + \\dfrac{b}{m} = \\dfrac{a+b}{m}$ <br\/> $x - y = \\dfrac{a}{m} - \\dfrac{b}{m} = \\dfrac{a-b}{m.}$ <\/span> <br\/><br\/>B\u00e0i gi\u1ea3i:<\/span><br\/> <br\/> $ 5 + \\dfrac{5}{3} - \\dfrac{3}{2} = \\dfrac{30}{6} + \\dfrac{10}{6} - \\dfrac{9}{6} = \\dfrac{30+10-9}{6}= \\dfrac{31}{6} $ <br\/> <br\/> K\u1ebft qu\u1ea3 ph\u00e9p t\u00ednh l\u00e0 $\\dfrac{31}{6}.$<\/span><\/span> <br\/>"}]}]},"correct":"","level":"1","hint":"","answer":"","type":"json","extra_type":"","time":"0","user_id":"0","test":"0","date":"2019-09-30 09:22:42"},{"id":"70","post_id":"953","mon_id":"0","chapter_id":"0","question":"\u0110i\u1ec1n s\u1ed1 th\u00edch h\u1ee3p v\u00e0o ch\u1ed7 tr\u1ed1ng","options":{"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":[[["13"],["28"]]],"list":[{"point":5,"width":50,"content":"","type_input":"","ques":" T\u00ecm $x \\in \\mathbb{Q} $ bi\u1ebft: $ x + \\dfrac{2}{7} = \\dfrac{3}{4} $ <br\/> \u0110\u00e1p s\u1ed1: <\/b> $ x$= <div class=\"frac123\"><div class=\"ts\">_input_<\/div><div class=\"ms\">_input_<\/div><\/div>","explain":" $x + \\dfrac{2}{7} = \\dfrac{3}{4} $ <br\/> $\\Rightarrow x = \\dfrac{3}{4} - \\dfrac{2}{7} $ <br\/> $\\Rightarrow x = \\dfrac{13}{28}$ <br\/> <br\/> Gi\u00e1 tr\u1ecb c\u1ee7a x l\u00e0 $\\dfrac{13}{28}.$ <\/span><\/span> <br\/>"}]}]},"correct":"","level":"1","hint":"","answer":"","type":"json","extra_type":"","time":"0","user_id":"0","test":"0","date":"2019-09-30 09:22:42"}]}