(x+y)^6/(x+y)^4-(x-y)^5/(x-y)^3 化简 ..
问题描述:
(x+y)^6/(x+y)^4-(x-y)^5/(x-y)^3 化简 ..
答
(x+y)^6/(x+y)^4-(x-y)^5/(x-y)^3
=(x+y)^(6-4)-(x-y)^(5-3)
=(x+y)^2-(x-y)^2
=(x+y+x-y)(x+y-x+y)
=(2x)(2y)
=4xy