化简求值:[(x-2y)²-4 y+2xy]÷2x其中x=-1,y=2
问题描述:
化简求值:[(x-2y)²-4 y+2xy]÷2x其中x=-1,y=2
答
化简原式
=[(x-2y)²+2y(x-2y)]÷2x
=(x-2y)(x-2y+2y)÷2x
=(x-2y)/2;
=(-1-2×2)/2
= -5/2