Giải bài toán bằng cách lập phương trình

Home Lớp 8 Toán lớp 8 - Sách Kết nối tri thứcBài tập trung bình

Bài 26 - Giải bài toán bằng cách lập phương trình

{"common":{"save":0,"post_id":"6634","level":2,"total":10,"point":10,"point_extra":0},"segment":[{"id":"6564","post_id":"6634","mon_id":"1158921","chapter_id":"1158933","question":"Hi\u1ec7u c\u1ee7a hai s\u1ed1 t\u1ef1 nhiên là 12. N\u1ebfu g\u1ecdi s\u1ed1 l\u1edbn là x thì s\u1ed1 bé là<\/p>","options":["A.<\/strong> $x-12$<\/span>","B.<\/strong> $12-x$<\/span>","C.<\/strong> $x+12$<\/span>","D.<\/strong> $12x$<\/span>"],"correct":"1","level":"2","hint":"","answer":"Vì hi\u1ec7u hai s\u1ed1 t\u1ef1 nhiên là 12 nên n\u1ebfu s\u1ed1 l\u1edbn là $x$<\/span> thì s\u1ed1 bé là   A.<\/strong> $x-12$<\/span> .<\/span><\/p>","type":"choose","extra_type":"classic","time":"0","user_id":"131","test":"0","date":"2023-08-27 10:13:33","option_type":"math","len":0},{"id":"6565","post_id":"6634","mon_id":"1158921","chapter_id":"1158933","question":"Hi\u1ec7u c\u1ee7a hai s\u1ed1 t\u1ef1 nhiên là 12. N\u1ebfu g\u1ecdi s\u1ed1 l\u1edbn là x thì bi\u1ec3u th\u1ee9c bi\u1ec3u th\u1ecb t\u1ed5ng c\u1ee7a hai s\u1ed1 t\u1ef1 nhiên \u0111ó là<\/p>","options":["A.<\/strong> $x+12$<\/span>","B.<\/strong> $2x-12$<\/span>","C.<\/strong> $2x+12$<\/span>","D.<\/strong> $x-12$<\/span>"],"correct":"2","level":"2","hint":"","answer":"S\u1ed1 bé là  $x-12$<\/span> .<\/p>T\u1ed5ng c\u1ee7a hai s\u1ed1 t\u1ef1 nhiên \u0111ó là  $x+x-12$<\/span> = $2x-12$<\/span> .<\/p>\u0110áp án \u0111úng là   B.<\/strong> $2x-12$<\/span> .<\/span><\/p>","type":"choose","extra_type":"classic","time":"0","user_id":"131","test":"0","date":"2023-08-27 10:16:06","option_type":"math","len":0},{"id":"6567","post_id":"6634","mon_id":"1158921","chapter_id":"1158933","question":"Hai kho có t\u1ea5t c\u1ea3 là 200 t\u1ea5n thóc. N\u1ebfu chuy\u1ec3n 10 t\u1ea5n thóc t\u1eeb kho th\u1ee9 nh\u1ea5t sang kho th\u1ee9 hai thì s\u1ed1 t\u1ea5n thóc \u1edf hai kho b\u1eb1ng nhau.<\/p>N\u1ebfu g\u1ecdi s\u1ed1 thóc có trong kho th\u1ee9 nh\u1ea5t lúc \u0111\u1ea7u là x (t\u1ea5n) thì s\u1ed1 thóc có kho th\u1ee9 hai sau khi \u0111ã chuy\u1ec3n là<\/p>","options":["A.<\/strong> $200-x$<\/span> t\u1ea5n","B.<\/strong> $x-200$<\/span> t\u1ea5n","C.<\/strong> $210-x$<\/span> t\u1ea5n","D.<\/strong> $x-210$<\/span> t\u1ea5n"],"correct":"3","level":"2","hint":"","answer":"S\u1ed1 thóc có trong kho th\u1ee9 hai lúc \u0111\u1ea7u là  $200-x$<\/span>  t\u1ea5n.<\/p>Vì chuy\u1ec3n 10 t\u1ea5n thóc t\u1eeb kho th\u1ee9 nh\u1ea5t sang kho th\u1ee9 hai nên s\u1ed1 thóc có trong th\u1ee9 hai sau khi chuy\u1ec3n là $200-x+10$<\/span> = $210-x$<\/span>  t\u1ea5n.<\/p>\u0110áp án \u0111úng là   C.<\/strong> $210-x$<\/span> t\u1ea5n .<\/span><\/p>","type":"choose","extra_type":"classic","time":"0","user_id":"131","test":"0","date":"2023-08-27 10:20:55","option_type":"math","len":0}]}