已知x^2-4x+2=0,则(x-1)^2-2(x+1)的值为______
问题描述:
已知x^2-4x+2=0,则(x-1)^2-2(x+1)的值为______
答
(x-1)^2-2(x+1)
=x²-2x+1-2x-2
=x²-4x+2-3
=-3