{"common":{"save":0,"post_id":"779","level":3,"total":10,"point":10,"point_extra":0},"segment":[{"id":"1221","post_id":"779","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":10,"ques":" T\u00ecm s\u1ed1 nguy\u00ean x, bi\u1ebft:<br\/>|7 - x| + (-31) = -19","select":["A. x = 5","B. x = 12","C. x = -5 ho\u1eb7c x = 19","D. x = -5 ho\u1eb7c x = 12"],"hint":"","explain":" <span class='basic_left'><span class='basic_green'>H\u01b0\u1edbng d\u1eabn:<\/span><br\/> Kho\u1ea3ng c\u00e1ch t\u1eeb \u0111i\u1ec3m a \u0111\u1ebfn \u0111i\u1ec3m 0 tr\u00ean tr\u1ee5c s\u1ed1 l\u00e0 gi\u00e1 tr\u1ecb tuy\u1ec7t \u0111\u1ed1i c\u1ee7a s\u1ed1 nguy\u00ean a<br\/>N\u00ean:<b> |x| = a (a $\\in$ N) th\u00ec x = a ho\u1eb7c x = -a<\/b><\/span> <br\/><br\/><span class='basic_left'><span class='basic_left'><span class='basic_green'>B\u00e0i gi\u1ea3i:<\/span><br\/> $\\begin{align*}|7 - x| + (-31) &= -19\\\\|7 - x|&= -19 - (-31) \\\\|7 - x|&= -19 + 31\\\\|7 - x|&= 31 - 19\\\\|7 - x|&= 12\\end{align*}$<br\/>$\\Rightarrow$ 7 - x = 12 ho\u1eb7c 7 - x = -12<br\/>+) <br\/>$\\begin{align*}7 - x &= 12\\\\x&= 7 - 12\\\\x&= - (12 - 7)\\\\x&= -5\\end{align*}$<br\/>+) <br\/>$\\begin{align*}7 - x &= -12\\\\x&= 7 - (-12) \\\\x&= 7 + 12\\\\x&= 19\\end{align*}$<br\/>V\u1eady ta ch\u1ecdn \u0111\u00e1p \u00e1n \u0111\u00fang l\u00e0: <span class='basic_pink'> C. x = -5 ho\u1eb7c x = 19<\/span><\/span> <br\/><\/span><\/span>","column":2}]}]},"correct":"","level":"3","hint":"","answer":"","type":"json","extra_type":"","time":"0","user_id":"0","test":"0","date":"2019-09-30 09:14:50"},{"id":"1222","post_id":"779","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":10,"ques":" T\u00ecm s\u1ed1 nguy\u00ean x, bi\u1ebft:<br\/>|205 - x| - |-40| = |-200|","select":["A. x = 35","B. x = -445","C. x = 35 ho\u1eb7c x = -445","D. x = -35 ho\u1eb7c x = 445"],"hint":"","explain":" <span class='basic_left'><span class='basic_green'>H\u01b0\u1edbng d\u1eabn:<\/span><br\/> Kho\u1ea3ng c\u00e1ch t\u1eeb \u0111i\u1ec3m a \u0111\u1ebfn \u0111i\u1ec3m 0 tr\u00ean tr\u1ee5c s\u1ed1 l\u00e0 gi\u00e1 tr\u1ecb tuy\u1ec7t \u0111\u1ed1i c\u1ee7a s\u1ed1 nguy\u00ean a<br\/>N\u00ean:<b> |x| = a (a $\\in$ N) th\u00ec x = a ho\u1eb7c x = -a<\/b><\/span> <br\/><br\/><span class='basic_left'><span class='basic_left'><span class='basic_green'>B\u00e0i gi\u1ea3i:<\/span><br\/> $\\begin{align*}|205 - x| - |-40| &= |-200|\\\\|205 - x| - 40&=200 \\\\|205 - x|&= 200 + 40\\\\|205 - x|&= 240\\end{align*}$<br\/>$\\Rightarrow$ 205 - x = 240 ho\u1eb7c 205 - x = -240<br\/>+) <br\/>$\\begin{align*}205 - x &= 240\\\\x&= 205 - 240\\\\x&= - (240 - 205)\\\\x&= -35\\end{align*}$<br\/>+) <br\/>$\\begin{align*}205 - x &= -240\\\\x&= 205 - (-240) \\\\x&= 205 + 240\\\\x&= 445\\end{align*}$<br\/>V\u1eady ta ch\u1ecdn \u0111\u00e1p \u00e1n \u0111\u00fang l\u00e0: <span class='basic_pink'> D. x = -35 ho\u1eb7c x = 445<\/span><\/span> <br\/><\/span><\/span>","column":2}]}]},"correct":"","level":"3","hint":"","answer":"","type":"json","extra_type":"","time":"0","user_id":"0","test":"0","date":"2019-09-30 09:14:50"},{"id":"1223","post_id":"779","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":[[["0"],["0"]]],"list":[{"point":10,"width":60,"type_input":"","ques":"T\u00ecm s\u1ed1 nguy\u00ean a, b bi\u1ebft: |a| + |b| = 0<br\/>a = _input_, b = _input_","hint":"","explain":"<span class='basic_left'><span class='basic_green'>B\u00e0i gi\u1ea3i:<\/span><br\/> Ta c\u00f3:<br\/> |a| $\\ge $ 0 v\u1edbi m\u1ecdi a <br\/> |b| $\\ge $ 0 v\u1edbi m\u1ecdi b <br\/>M\u00e0 |a| + |b| = 0<br\/>$\\Rightarrow$ |a| = 0 ho\u1eb7c |b| = 0<br\/>$\\Rightarrow$ a = 0 ho\u1eb7c b = 0<br\/>V\u1eady c\u00e1c s\u1ed1 c\u1ea7n \u0111i\u1ec1n v\u00e0o \u00f4 tr\u1ed1ng l\u1ea7n l\u01b0\u1ee3t t\u1eeb tr\u00e1i qua ph\u1ea3i l\u00e0: <span class='basic_pink'> 0; 0<\/span><br\/><\/span> <br\/><\/span>"}]}]},"correct":"","level":"3","hint":"","answer":"","type":"json","extra_type":"","time":"0","user_id":"0","test":"0","date":"2019-09-30 09:14:50"}]}