已知x2+4x-4=0求3(x-2)-6(x+1)(x-1)的值

Question

如题所述

Answer 1

x²+4x+4=8
(x+2)²=8
x=-2±2√2
3(x-2)-6(x+1)(x-1)
=3x-6-6x²+6
=-6x²+3x=-6(4-4x)+3x
=27x-24
=27(-2±2√2)-24
=-78±54√2本回答被网友采纳