{"common":{"save":0,"post_id":"6544","level":1,"total":10,"point":10,"point_extra":0},"segment":[{"id":"5848","post_id":"6544","mon_id":"1158921","chapter_id":"1158928","question":"<p>\u0110\u1eb3ng th\u1ee9c nào sau \u0111ây là h\u1eb1ng \u0111\u1eb3ng th\u1ee9c?<\/p>","options":["<strong>A. <\/strong><span class=\"math-tex\">$3y+2=2y+1$<\/span>","<strong>B. <\/strong><span class=\"math-tex\">$(x-2)x=x^2+2x$<\/span>","<strong>C. <\/strong><span class=\"math-tex\">$(x+y)z=xz+yz$<\/span>","<strong>D. <\/strong><span class=\"math-tex\">$3-y=y+3$<\/span>"],"correct":"3","level":"1","hint":"<p>H\u1eb1ng \u0111\u1eb3ng th\u1ee9c là \u0111\u1eb3ng th\u1ee9c mà hai v\u1ebf luôn cùng nh\u1eadn m\u1ed9t giá tr\u1ecb khi thay các ch\u1eef trong \u0111\u1eb3ng th\u1ee9c b\u1eb1ng các s\u1ed1 tùy ý.<\/p>","answer":"<p><strong>A. <\/strong><span class=\"math-tex\">$3y+2=2y+1$<\/span>: thay y = 0 thì hai v\u1ebf c\u1ee7a \u0111\u1eb3ng th\u1ee9c không b\u1eb1ng nhau.<\/p><p><strong>B. <\/strong><span class=\"math-tex\">$(x-2)x=x^2+2x$<\/span>: thay x = 2 thì hai v\u1ebf c\u1ee7a \u0111\u1eb3ng th\u1ee9c không b\u1eb1ng nhau.<\/p><p><strong>D. <\/strong><span class=\"math-tex\">$3-y=y+3$<\/span>: thay y = 1 thì hai v\u1ebf c\u1ee7a \u0111\u1eb3ng th\u1ee9c không b\u1eb1ng nhau.<\/p><p>Ch\u1ecdn <span style=\"color:#16a085;\"><strong>C. <\/strong><span class=\"math-tex\">$(x+y)z=xz+yz$<\/span><\/span><\/p>","type":"choose","extra_type":"classic","time":"0","user_id":"131","test":"0","date":"2023-07-04 14:20:12","option_type":"math","len":0},{"id":"5850","post_id":"6544","mon_id":"1158921","chapter_id":"1158928","question":"<p>Thay <input class=\"_tit_hoi\" disabled=\"disabled\" type=\"text\"\/> b\u1eb1ng bi\u1ec3u th\u1ee9c thích h\u1ee3p:<\/p><p>(3x – y)(3x + y) = <input class=\"_tit_hoi\" disabled=\"disabled\" type=\"text\"\/> – y² <\/p>","options":["<strong>A. <\/strong>x²","<strong>B. <\/strong>4x²","<strong>C. <\/strong>9x²","<strong>D. <\/strong>3x²"],"correct":"3","level":"1","hint":"","answer":"<p>(3x – y)(3x + y) = 9x² + 3xy – 3xy – y² = <span style=\"color:#16a085;\"><strong>9x²<\/strong><\/span> – y²<\/p><p>V\u1eady bi\u1ec3u th\u1ee9c c\u1ea7n \u0111i\u1ec1n là <span style=\"color:#16a085;\"><strong>9x²<\/strong><\/span>.<\/p><p>Ch\u1ecdn <span style=\"color:#16a085;\"><strong>C. <\/strong>9x²<\/span><\/p>","type":"choose","extra_type":"shape2","time":"0","user_id":"131","test":"0","date":"2023-07-04 14:24:56","option_type":"txt","len":0},{"id":"5853","post_id":"6544","mon_id":"1158921","chapter_id":"1158928","question":"<p>Thay d\u1ea5u <input class=\"_tit_hoi\" disabled=\"disabled\" type=\"text\"\/> b\u1eb1ng bi\u1ec3u th\u1ee9c thích h\u1ee3p:<\/p><p>( <input class=\"_tit_hoi\" disabled=\"disabled\" type=\"text\"\/> + b)( <input class=\"_tit_hoi\" disabled=\"disabled\" type=\"text\"\/> – b) = 4a² – b²<\/p>","options":["<strong>A. <\/strong>2a","<strong>B. <\/strong>2x","<strong>C. <\/strong>4a","<strong>D. <\/strong>a"],"correct":"1","level":"1","hint":"<p>H\u1eb1ng \u0111\u1eb3ng th\u1ee9c hi\u1ec7u hai bình ph\u01b0\u01a1ng: A² – B² = (A + B)(A – B).<\/p>","answer":"<p>Ta có: 4a² – b² = (2a)² – b² = (<span style=\"color:#16a085;\"><strong>2a<\/strong><\/span> – b)(<span style=\"color:#16a085;\"><strong>2a<\/strong><\/span> + b)<\/p><p>V\u1eady bi\u1ec3u th\u1ee9c c\u1ea7n \u0111i\u1ec1n là <span style=\"color:#16a085;\"><strong>2a<\/strong><\/span>.<\/p><p>Ch\u1ecdn <span style=\"color:#16a085;\"><strong>A. <\/strong>2a<\/span><\/p>","type":"choose","extra_type":"classic","time":"0","user_id":"131","test":"0","date":"2023-07-04 14:31:50","option_type":"txt","len":0}]}