{"common":{"save":0,"post_id":"4587","level":3,"total":10,"point":10,"point_extra":0},"segment":[{"id":"6711","post_id":"4587","mon_id":"1158113","chapter_id":"1158128","question":"<p>Tìm s\u1ed1 nguyên x, bi\u1ebft <strong>( x - 19) . ( -25 + 5 . x ) = 0<\/strong><\/p><div class=\"lt123_imgs\"><img class=\"img_dd small\" src=\"\/data\/library\/hoa-cay\/cay2.png\" \/><\/div>","options":["x = 19 ho\u1eb7c x = 5","x = -19 ho\u1eb7c x = 5","x = 19 ho\u1eb7c x = -5"],"correct":"1","level":"3","hint":"<p>Tích c\u1ee7a hai th\u1eeba s\u1ed1 b\u1eb1ng 0 thì m\u1ed9t trong hai th\u1eeba s\u1ed1 \u0111ó b\u1eb1ng 0.<\/p>","answer":"<p><strong>( x - 19) . ( -25 + 5 . x ) = 0<\/strong><\/p><p><strong>x - 19 = 0 ho\u1eb7c -25 + 5 . x = 0<\/strong><\/p><p>Tr\u01b0\u1eddng h\u1ee3p 1: x - 19 = 0 thì x = 19<\/p><p>Tr\u01b0\u1eddng h\u1ee3p 2:<\/p><p>-25 + 5 . x = 0 <\/p><p> 5 . x = 0 - (-25)<\/p><p> 5 . x = 25<\/p><p> x = 25 : 5<\/p><p> x = 5<\/p><p>V\u1eady \u0111áp án \u0111úng là <span style=\"color:#16a085;\"><strong>x = 19 ho\u1eb7c x = 5<\/strong><\/span><\/p>","type":"choose","extra_type":"classic","time":"0","user_id":"132","test":"3","date":"2021-08-27 12:05:48","option_type":"txt","len":2},{"id":"6713","post_id":"4587","mon_id":"1158113","chapter_id":"1158128","question":"<p>Tính t\u1ed5ng (-1) + 2 + (-3) + 4 + ... + (-49) + 50<\/p>","options":["-225","-25","-22","25"],"correct":"4","level":"3","hint":"<p>\u0110\u1ec3 ý (-1) + 2 = (-3) + 4 = ... = (-49) + 50<strong> = 1<\/strong> <\/p><p>Vì t\u1ed5ng<strong> (-1) + 2 + (-3) + 4 + ... + (-49) + 50<\/strong> có 50 s\u1ed1 h\u1ea1ng, c\u1ee9 hai s\u1ed1 h\u1ea1ng ghép l\u1ea1i thì có t\u1ed5ng là 1 nên có 50 : 2 =25 c\u1eb7p s\u1ed1)<\/p>","answer":"<p>Ta có: (-1) + 2 + (-3) + 4 + ... + (-49) + 50<\/p><p> = [ (-1) + 2] + [ (-3) + 4] + ... + [ (-49) + 50]<\/p><p>= 1 + 1 + ... + 1 ( 25 s\u1ed1 1 )<\/p><p>= 25 <\/p><p>V\u1eady \u0111áp án là <span style=\"color:#16a085;\"><strong>25<\/strong><\/span>.<\/p>","type":"choose","extra_type":"classic","time":"0","user_id":"132","test":"3","date":"2021-08-27 12:16:32","option_type":"number","len":0},{"id":"6714","post_id":"4587","mon_id":"1158113","chapter_id":"1158128","question":"<p>T\u1ed5ng c\u1ee7a s\u1ed1 nguyên âm nh\u1ecf nh\u1ea5t có ba ch\u1eef s\u1ed1 v\u1edbi s\u1ed1 nguyên d\u01b0\u01a1ng l\u1edbn nh\u1ea5t có m\u1ed9t ch\u1eef s\u1ed1 là bao nhiêu?<\/p><div class=\"lt123_imgs\"><img class=\"img_dd small\" src=\"\/data\/library\/hoa-cay\/bouquet.png\" \/><\/div>","options":["-990","-981","-91","-1008"],"correct":"1","level":"3","hint":"<p>S\u1ed1 nguyên âm nh\u1ecf nh\u1ea5t có ba ch\u1eef s\u1ed1 là -999.<\/p><p>S\u1ed1 nguyên d\u01b0\u01a1ng l\u1edbn nh\u1ea5t có m\u1ed9t ch\u1eef s\u1ed1 là 9.<\/p><p>Tính t\u1ed5ng c\u1ee7a hai s\u1ed1 nguyên trên.<\/p>","answer":"<p>T\u1ed5ng c\u1ee7a s\u1ed1 nguyên âm nh\u1ecf nh\u1ea5t có ba ch\u1eef s\u1ed1 v\u1edbi s\u1ed1 nguyên d\u01b0\u01a1ng l\u1edbn nh\u1ea5t có m\u1ed9t ch\u1eef s\u1ed1<\/p><p>S\u1ed1 nguyên âm nh\u1ecf nh\u1ea5t có ba ch\u1eef s\u1ed1 là -999.<\/p><p>S\u1ed1 nguyên d\u01b0\u01a1ng l\u1edbn nh\u1ea5t có m\u1ed9t ch\u1eef s\u1ed1 là 9.<\/p><p>T\u1ed5ng c\u1ee7a hai s\u1ed1 nguyên \u0111ó là: (-999) + 9 = - (999 - 9) = -990<\/p><p>V\u1eady \u0111áp án \u0111úng là <span style=\"color:#16a085;\"><strong>-990<\/strong><\/span>.<\/p>","type":"choose","extra_type":"cloud","time":"0","user_id":"132","test":"3","date":"2021-08-27 12:21:36","option_type":"txt","len":0}]}