Question

求助几道因式分解要过程！

(a+b)^4-(a+b)^2
x^2(x-y)+y^2(x-y)
(7m+3n)^2-(5m+7n)^2

Answer 1

1、(a+b)^4-(a+b)^2
=＜（a+b)^ 2+a+b)＞＜（a+b)^2-a-b＞
=(a+b)(a+b+1)＜（a+b)^2-a-b＞
2、x^2(x-y)+y^2(x-y)
=(x-y)(x^2-y^2)
=(x-y)(x+y)(x-y)
=(x+y)(x-y)^2
3、(7m+3n)^2-(5m+7n)^2
=(7m+3n+5m+7n)(7m+3n-5m-7n)
=(12m+10n)(2m-4n)
=4(6m+5n)(m-2n)

追问

确定对？

追答

确定