x+y分之x-y除以(x-y)的平方怎么算
问题描述：
x+y分之x-y除以(x-y)的平方怎么算
答
(x-y)/(x+y)除以(x-y)^2
=(x-y)/(x+y)*(x-y)^2
=1/(x+y)(x-y)
答
原式=x-y/x+y×1/(x-y)²
（约分x-y）=1/x+y×1/x-y
=1/x²-y²