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

(x-y)/(x+y)除以(x-y)^2
=(x-y)/(x+y)*(x-y)^2
=1/(x+y)(x-y)

原式=x-y/x+y×1/(x-y)²
(约分x-y)=1/x+y×1/x-y
=1/x²-y²