{"common":{"save":0,"post_id":"962","level":1,"total":20,"point":5,"point_extra":0},"segment":[{"id":"151","post_id":"962","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\/6.jpg' \/><\/center> N\u1ebfu $ x > 0 $ th\u00ec $ \\mid x \\mid $ b\u1eb1ng : ","select":["A. $ x $","B. $ -x $","C. $ 0 $ "],"explain":" <span class='basic_left'><span class='basic_green'>H\u01b0\u1edbng d\u1eabn:<\/span><br\/> <i> Gi\u00e1 tr\u1ecb tuy\u1ec7t \u0111\u1ed1i <\/i> c\u1ee7a s\u1ed1 h\u1eefu t\u1ec9 $x$, k\u00ed hi\u1ec7u $ \\mid x \\mid $ l\u00e0 kho\u1ea3ng c\u00e1ch t\u1eeb \u0111i\u1ec3m $x$ t\u1edbi \u0111i\u1ec3m $0$ tr\u00ean tr\u1ee5c s\u1ed1. <br\/> Ta c\u00f3: $ \\mid x \\mid = \\begin{cases} x \\text { n\u1ebfu } x \\geq 0 \\\\ -x \\text { n\u1ebfu } x < 0. \\end{cases} $ <\/span> <br\/><br\/><span class='basic_green'>B\u00e0i gi\u1ea3i:<\/span><br\/> <br\/> Ta c\u00f3: $ \\mid x \\mid = \\begin{cases} x \\text { n\u1ebfu } x \\geq 0 \\\\ -x \\text { n\u1ebfu } x < 0. \\end{cases} $ <br\/> V\u1eady v\u1edbi $ x > 0 $ th\u00ec $ \\mid x \\mid = x $ <br\/> <br\/> <span class='basic_pink'> \u0110\u00e1p \u00e1n \u0111\u00fang l\u00e0 A.<\/span><\/span> <br\/>","column":3}]}]},"correct":"","level":"1","hint":"","answer":"","type":"json","extra_type":"","time":"0","user_id":"0","test":"0","date":"2019-09-30 09:22:43"},{"id":"152","post_id":"962","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\/6.jpg' \/><\/center> N\u1ebfu $ x < 0 $ th\u00ec $ \\mid x \\mid $ b\u1eb1ng : ","select":["A. $ x $","B. $ -x $","C. $ 0 $ "],"explain":" <span class='basic_left'><span class='basic_green'>H\u01b0\u1edbng d\u1eabn:<\/span><br\/> <i> Gi\u00e1 tr\u1ecb tuy\u1ec7t \u0111\u1ed1i <\/i> c\u1ee7a s\u1ed1 h\u1eefu t\u1ec9 $x$, k\u00ed hi\u1ec7u $ \\mid x \\mid $ l\u00e0 kho\u1ea3ng c\u00e1ch t\u1eeb \u0111i\u1ec3m $x$ t\u1edbi \u0111i\u1ec3m $0$ tr\u00ean tr\u1ee5c s\u1ed1. <br\/> Ta c\u00f3: $ \\mid x \\mid = \\begin{cases} x \\text { n\u1ebfu } x \\geq 0 \\\\ -x \\text { n\u1ebfu } x < 0. \\end{cases} $ <\/span> <br\/><br\/><span class='basic_green'>B\u00e0i gi\u1ea3i:<\/span><br\/> <br\/> Ta c\u00f3: $ \\mid x \\mid = \\begin{cases} x \\text { n\u1ebfu } x \\geq 0 \\\\ -x \\text { n\u1ebfu } x < 0. \\end{cases} $ <br\/> V\u1eady v\u1edbi $ x < 0 $ th\u00ec $ \\mid x \\mid = -x $ <br\/> <br\/> <span class='basic_pink'> \u0110\u00e1p \u00e1n \u0111\u00fang l\u00e0 B.<\/span><\/span> <br\/>","column":3}]}]},"correct":"","level":"1","hint":"","answer":"","type":"json","extra_type":"","time":"0","user_id":"0","test":"0","date":"2019-09-30 09:22:43"},{"id":"153","post_id":"962","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\/6.jpg' \/><\/center> V\u1edbi m\u1ecdi $ x \\in \\mathbb{Q}$ ta lu\u00f4n c\u00f3: $ \\mid x \\mid \\geq x $ \u0111\u00fang hay sai? ","select":["A. \u0110\u00fang ","B. Sai "],"explain":" <span class='basic_left'><span class='basic_green'>H\u01b0\u1edbng d\u1eabn:<\/span><br\/> <i> Gi\u00e1 tr\u1ecb tuy\u1ec7t \u0111\u1ed1i <\/i> c\u1ee7a s\u1ed1 h\u1eefu t\u1ec9 $x$, k\u00ed hi\u1ec7u $ \\mid x \\mid $ l\u00e0 kho\u1ea3ng c\u00e1ch t\u1eeb \u0111i\u1ec3m $x$ t\u1edbi \u0111i\u1ec3m $0$ tr\u00ean tr\u1ee5c s\u1ed1. <br\/> V\u1edbi m\u1ecdi $ x \\in \\mathbb{Q}$ ta lu\u00f4n c\u00f3: <br\/> $ \\quad \\mid x \\mid \\geq 0; \\mid x \\mid = \\mid -x \\mid; \\mid x \\mid \\geq x. $ <br\/><br\/><span class='basic_green'>B\u00e0i gi\u1ea3i:<\/span><br\/> V\u1edbi $ x < 0 $ th\u00ec $ \\mid x \\mid = -x > 0.$ Suy ra $ \\mid x \\mid > x$ <br\/> V\u1edbi $ x > 0 $ th\u00ec $ \\mid x \\mid = x > 0.$ Suy ra $ \\mid x \\mid = x$ <br\/> Suy ra, v\u1edbi m\u1ecdi $ x \\in \\mathbb{Q}$ ta lu\u00f4n c\u00f3: $ \\mid x \\mid \\geq x $ <br\/> <br\/> <span class='basic_pink'> \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 09:22:43"}]}