{"common":{"save":0,"post_id":"973","level":2,"total":20,"point":5,"point_extra":0},"segment":[{"id":"271","post_id":"973","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\/9.jpg' \/><\/center>So s\u00e1nh hai s\u1ed1 h\u1eefu t\u1ec9 $\\dfrac{76}{-89}$ v\u00e0 $\\dfrac{-5}{9}$ b\u1eb1ng c\u00e1ch nh\u00e2n ch\u00e9o ta \u0111\u01b0\u1ee3c: ","select":["A. $\\dfrac{76}{-89}$ < $\\dfrac{-5}{9}$ ","B. $\\dfrac{76}{-89}$ = $\\dfrac{-5}{9}$ ","C. $\\dfrac{76}{-89}$ > $\\dfrac{-5}{9}$"],"explain":" <span class='basic_left'><span class='basic_green'>H\u01b0\u1edbng d\u1eabn:<\/span> <br\/> $\\bullet $ <b> So s\u00e1nh hai s\u1ed1 h\u1eefu t\u1ec9 b\u1eb1ng c\u00e1ch nh\u00e2n ch\u00e9o: <\/b> <br\/> So s\u00e1nh $\\dfrac{a}{b}$ v\u00e0 $\\dfrac{c}{d}$ v\u1edbi $bd > 0 $ <br\/> * N\u1ebfu t\u00edch $ad > bc$ th\u00ec $\\dfrac{a}{b} > \\dfrac{c}{d}$ <br\/> * N\u1ebfu t\u00edch $ad < bc$ th\u00ec $\\dfrac{a}{b} < \\dfrac{c}{d}$ <\/span> <br\/> <br\/> <span class='basic_green'>B\u00e0i gi\u1ea3i:<\/span><br\/> Vi\u1ebft l\u1ea1i t\u1ec9 s\u1ed1 $\\dfrac{76}{-89} = \\dfrac{-76}{89}$ <br\/> Ta ph\u1ea3i so s\u00e1nh $\\dfrac{-76}{89}$ v\u00e0 $\\dfrac{-5}{9}$ <br\/> C\u00f3: $(-76) . 9 = -684 $ v\u00e0 $89 . (-5) = -445 $ <br\/> M\u00e0 $-684 < -445$ suy ra $\\dfrac{-76}{89} < \\dfrac{-5}{9}$ <br\/> Hay $\\dfrac{76}{-89} < \\dfrac{-5}{9} $ <br\/> <br\/> <span class='basic_pink'> \u0110\u00e1p \u00e1n c\u1ea7n ch\u1ecdn l\u00e0 A. <\/span><\/span> ","column":3}]}]},"correct":"","level":"2","hint":"","answer":"","type":"json","extra_type":"","time":"0","user_id":"0","test":"0","date":"2019-09-30 09:22:45"},{"id":"272","post_id":"973","mon_id":"0","chapter_id":"0","question":"\u0110i\u1ec1n \u0111\u00e1p \u00e1n \u0111\u00fang v\u00e0o \u00f4 tr\u1ed1ng","options":{"time":24,"part":[{"title":"\u0110i\u1ec1n \u0111\u00e1p \u00e1n \u0111\u00fang v\u00e0o \u00f4 tr\u1ed1ng","title_trans":"","temp":"fill_the_blank","correct":[[["121"],["2"]]],"list":[{"point":5,"width":50,"type_input":"","ques":" T\u00ecm $x$ trong t\u1ec9 l\u1ec7 th\u1ee9c: $ \\dfrac{52}{2x-1} = \\dfrac{13}{30} $ <br\/> <b> \u0110\u00e1p s\u1ed1: <\/b> $ x$ = <div class=\"frac123\"><div class=\"ts\">_input_<\/div><div class=\"ms\">_input_<\/div><\/div>","explain":" \u00c1p d\u1ee5ng t\u00ednh ch\u1ea5t c\u1ee7a t\u1ec9 l\u1ec7 th\u1ee9c ta c\u00f3: <br\/> $ \\dfrac{52}{2x-1} = \\dfrac{13}{30} \\\\ \\Rightarrow 2x - 1 = \\dfrac{52.30}{13} = \\dfrac{1560}{13} = 120 \\\\ \\Rightarrow 2x = 120 + 1 = 121 \\\\ \\Rightarrow x = 121 : 2 = \\dfrac{121}{2} $ <br\/> <br\/> <span class='basic_pink'> V\u1eady gi\u00e1 tr\u1ecb c\u1ee7a $x$ l\u00e0 $ \\dfrac{121}{2} $ <\/span><\/span>"}]}]},"correct":"","level":"2","hint":"","answer":"","type":"json","extra_type":"","time":"0","user_id":"0","test":"0","date":"2019-09-30 09:22:45"},{"id":"273","post_id":"973","mon_id":"0","chapter_id":"0","question":"\u0110i\u1ec1n \u0111\u00e1p \u00e1n \u0111\u00fang v\u00e0o \u00f4 tr\u1ed1ng","options":{"time":24,"part":[{"title":"\u0110i\u1ec1n \u0111\u00e1p \u00e1n \u0111\u00fang v\u00e0o \u00f4 tr\u1ed1ng","title_trans":"","temp":"fill_the_blank","correct":[[["-4"]]],"list":[{"point":5,"width":50,"type_input":"","ques":" T\u00ecm $x$ trong t\u1ec9 l\u1ec7 th\u1ee9c: $ \\dfrac{x+3}{-4} = \\dfrac{5}{20}?$ <br\/> <b> \u0110\u00e1p s\u1ed1: <\/b> $ x = $ _input_","explain":" \u00c1p d\u1ee5ng t\u00ednh ch\u1ea5t c\u1ee7a t\u1ec9 l\u1ec7 th\u1ee9c ta c\u00f3: <br\/> $ \\dfrac{x+3}{-4} = \\dfrac{5}{20} \\\\ \\Rightarrow x + 3 = \\dfrac{(-4).5}{20} = -1 \\\\ \\Rightarrow x = -1 - 3 = -4 $ <br\/> <br\/> <span class='basic_pink'> V\u1eady gi\u00e1 tr\u1ecb c\u1ee7a $x$ l\u00e0 $ -4 $ <\/span><\/span>"}]}]},"correct":"","level":"2","hint":"","answer":"","type":"json","extra_type":"","time":"0","user_id":"0","test":"0","date":"2019-09-30 09:22:45"}]}