{"common":{"save":0,"post_id":"1020","level":2,"total":20,"point":5,"point_extra":0},"segment":[{"id":"471","post_id":"1020","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> So s\u00e1nh c\u1eb7p s\u1ed1 th\u1ef1c 2,(16) v\u00e0 2,(15) ta \u0111\u01b0\u1ee3c","select":["A. 2,(16) < 2,(15) ","B. 2,(16) > 2,(15) ","C. 2,(16) = 2,(15) "],"explain":" Ta c\u00f3: 2,(16) = 2,161616... <br\/> 2,(15) = 2,151515.. <br\/> M\u00e0 2,16... > 2,15... n\u00ean 2,(16) > 2,(15) <br\/> <br\/> <span class='basic_pink'> \u0110\u00e1p \u00e1n \u0111\u00fang l\u00e0 B <\/span><\/span> ","column":3}]}]},"correct":"","level":"2","hint":"","answer":"","type":"json","extra_type":"","time":"0","user_id":"0","test":"0","date":"2019-09-30 09:22:48"},{"id":"472","post_id":"1020","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":" T\u00ecm $x$, bi\u1ebft: <br\/> $\\sqrt{1,69} \\left( 2\\sqrt{x} + \\sqrt{\\dfrac{81}{121}} \\right)= \\dfrac{13}{10}$ ","select":["A. $x = \\dfrac{4}{121}$ ","B. $x = \\dfrac{1}{121}$ ","C. $x = \\dfrac{1}{22}$ ","D. $x = \\dfrac{16}{121}$ "],"explain":" <span class='basic_left'><span class='basic_green'>H\u01b0\u1edbng d\u1eabn:<\/span> <br\/> \u00c1p d\u1ee5ng $\\sqrt{x} = a (a \\geq 0)\\Rightarrow x = a^{2}$ <\/span> <br\/> <br\/> <span class='basic_green'>B\u00e0i gi\u1ea3i:<\/span><br\/> Ta c\u00f3: $\\sqrt{1,69} \\left( 2\\sqrt{x} + \\sqrt{\\dfrac{81}{121}}\\right) = \\dfrac{13}{10} \\\\ \\Rightarrow 1,3 . \\left( 2\\sqrt{x} + \\dfrac{9}{11} \\right) = 1,3 \\\\ \\Rightarrow 2\\sqrt{x} + \\dfrac{9}{11} = 1,3 : 1,3 = 1 \\\\ \\Rightarrow 2\\sqrt{x} = 1 - \\dfrac{9}{11} = \\dfrac{2}{11} \\\\ \\Rightarrow \\sqrt{x} = \\dfrac{2}{11} : 2 = \\dfrac{1}{11} \\\\ \\Rightarrow x = \\left(\\dfrac{1}{11} \\right)^{2} \\\\ \\Rightarrow x = \\dfrac{1}{121}$ <br\/> <br\/> <span class='basic_pink'> \u0110\u00e1p \u00e1n \u0111\u00fang l\u00e0 B. <\/span><\/span> ","column":2}]}]},"correct":"","level":"2","hint":"","answer":"","type":"json","extra_type":"","time":"0","user_id":"0","test":"0","date":"2019-09-30 09:22:48"},{"id":"473","post_id":"1020","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\/4.jpg' \/><\/center> T\u00ecm $x$, bi\u1ebft: <br\/> $\\left| \\dfrac{3}{5}\\sqrt{x} - \\dfrac{1}{20}\\right| - \\dfrac{3}{4} = \\dfrac{1}{5}$ ","select":["A. $x = \\dfrac{25}{9}$ ho\u1eb7c $x = \\dfrac{9}{4}$ ","B. $x = \\dfrac{25}{9}$ ho\u1eb7c $x = \\dfrac{-9}{4}$ ","C. $x = \\dfrac{25}{9}$ ","D. $x = \\dfrac{5}{3}$ "],"explain":" <span class='basic_left'><span class='basic_green'>H\u01b0\u1edbng d\u1eabn:<\/span> <br\/> \u00c1p d\u1ee5ng $\\sqrt{x} = a (a \\geq 0)\\Rightarrow x = a^{2}$ <br\/> <br\/> <span class='basic_green'>B\u00e0i gi\u1ea3i:<\/span><br\/> Ta c\u00f3: $\\left|\\dfrac{3}{5}\\sqrt{x} - \\dfrac{1}{20}\\right| - \\dfrac{3}{4} = \\dfrac{1}{5} \\\\ \\Rightarrow \\left| \\dfrac{3}{5}\\sqrt{x} - \\dfrac{1}{20} \\right| = \\dfrac{1}{5} + \\dfrac{3}{4} = \\dfrac{19}{20}$ <br\/> $\\Rightarrow \\dfrac{3}{5}\\sqrt{x} - \\dfrac{1}{20} = \\dfrac{19}{20}$ ho\u1eb7c $ \\dfrac{3}{5}\\sqrt{x} - \\dfrac{1}{20} = - \\dfrac{19}{20}$ <br\/> Tr\u01b0\u1eddng h\u1ee3p 1: $\\dfrac{3}{5}\\sqrt{x} - \\dfrac{1}{20} = \\dfrac{19}{20} \\\\ \\Rightarrow \\dfrac{3}{5} \\sqrt{x} = \\dfrac{19}{20} + \\dfrac{1}{20} = 1 \\\\ \\Rightarrow \\sqrt{x} = 1 : \\dfrac{3}{5} = \\dfrac{5}{3} \\\\ \\Rightarrow x = \\left(\\dfrac{5}{3}\\right)^{2} = \\dfrac{25}{9}$ <br\/> Tr\u01b0\u1eddng h\u1ee3p 2: $ \\dfrac{3}{5}\\sqrt{x} - \\dfrac{1}{20} = - \\dfrac{19}{20} $ <br\/> $ \\Rightarrow \\sqrt{x} = -\\dfrac{3}{2} < 0$ (lo\u1ea1i) <br\/> V\u1eady gi\u00e1 tr\u1ecb c\u1ee7a $x$ l\u00e0: $\\dfrac{25}{9}$<br\/> <br\/> <span class='basic_pink'> \u0110\u00e1p \u00e1n \u0111\u00fang l\u00e0 C. <\/span><\/span> ","column":2}]}]},"correct":"","level":"2","hint":"","answer":"","type":"json","extra_type":"","time":"0","user_id":"0","test":"0","date":"2019-09-30 09:22:48"}]}