F2 maths
回答 (2)
2013-07-02 12:21 am
✔ 最佳答案
(4x+y)^2-(4x-y)^2=[(4x+y)+(4x-y)][(4x+y)-(4x-y)]
=(4x+y+4x-y)(4x+y-4x+y)
=8x*2y
=16xy
2013-07-01 16:22:26 補充：
P.S. I used the identity a^2-b^2=(a+b)(a-b).
參考: myself :D
2013-07-01 7:42 pm
(4x+y)^2-(4x-y)^2
= (16x^2+8xy+y^2) - (16x^2-8xy+y^2)
= 16x^2+8xy+y^2 - 16x^2+8xy-y^2
=16xy
= (16x^2+8xy+y^2) - (16x^2-8xy+y^2)
= 16x^2+8xy+y^2 - 16x^2+8xy-y^2
=16xy
收錄日期: 2021-04-13 19:32:22
原文連結 [永久失效]:
https://hk.answers.yahoo.com/question/index?qid=20130701000051KK00078