计算:(x-y)^7/(y-x)^6+(-x-y)^3/(x+y)^2
问题描述:
计算:(x-y)^7/(y-x)^6+(-x-y)^3/(x+y)^2
答
(x-y)^7/(y-x)^6+(-x-y)^3/(x+y)^2
=(x-y)^7/(x-y)^6-(x+y)^3/(x+y)^2
=x-y-(x+y)
=x-y-x-y
=-2y