(x+y)^2/y^2-xy÷[-y^2+xy/(x-y)^2,x=0,y=根号10
问题描述：
(x+y)^2/y^2-xy÷[-y^2+xy/(x-y)^2,x=0,y=根号10
答
原式=(x+y)²/y(x-y)×(x-y)²/y(x+y)
=(x+y)(x-y)/y²
=(x²-y²)/y²
=（0-10）/10
=-1