因式分解:8(c+2d)^2-50(3c-d)^2
???
中三Maths 一問
2007-10-02 2:50 am
回答 (2)
2007-10-02 2:58 am
✔ 最佳答案
8(c+2d)^2-50(3c-d)^2 =2(4(c+2d)^2-25(3c-d)^2)
=2[ {2(c+2d)}^2 - {5(3c-d)}^2 ]
=2 {2(c+2d)+5(3c-d)} {2(c+2d)-5(3c-d)}
=2(17c-d)(-13c+9d)
=-2(17c-d)(13c-9d)
2007-10-02 3:19 am
呢個係我既答案！
8(c+2d)^2-50(3c-d)^2
=8(c^2+4cd+4d^2)-50(9c^2-6cd+d^2)
=8c^2+32cd+32d^2-450c^2+300cd-50d^2
=-442c^2+332cd-18d^2
=442c^2-332cd+18d^2
=(442c^2-332cd+18d^2)*1/2
=221c^2-166cd+9d^2
希望啱啦~~
8(c+2d)^2-50(3c-d)^2
=8(c^2+4cd+4d^2)-50(9c^2-6cd+d^2)
=8c^2+32cd+32d^2-450c^2+300cd-50d^2
=-442c^2+332cd-18d^2
=442c^2-332cd+18d^2
=(442c^2-332cd+18d^2)*1/2
=221c^2-166cd+9d^2
希望啱啦~~
收錄日期: 2021-04-13 13:42:23
原文連結 [永久失效]:
https://hk.answers.yahoo.com/question/index?qid=20071001000051KK04469