先化简,再求值:[(x+y)(x-y)-(x-y)2+2y(x-y)]÷人y,其中x=-2-3,y=2-3

2025-12-16 11:59:25
推荐回答(1个)
回答1:

原式=(x-y-x+得xy-y+得xy-得y)÷4y
=(4xy-4y)÷4y
=x-y,
当x=-得-

,y=得-
时,原式=-得-
-(得-
)=-4.