计算：(x^-1+y^-1)^2*(1/x^2+2xy+y^2)^-1
问题描述：
计算：(x^-1+y^-1)^2*(1/x^2+2xy+y^2)^-1
答
(x^-1+y^-1)^2*(1/x^2+2xy+y^2)^-1
=[(x+y)/(xy)]²*[1/(x+y)²]^(-1)
=(x+y)²/(xy)² *(x+y)²
=(x+y)^4/(xy)²