-(x-y)^2-2(y-x)^2-5(x-y)^2+8(x-y)^2化简

题目

-(x-y)^2-2(y-x)^2-5(x-y)^2+8(x-y)^2化简

答案

(y-x)²
=[-1*(x-y)]²
=(-1)²*(x-y)²
=1*(x-y)²
=(x-y)²
所以原式=(-1-2-5+8)(x-y)²
=0