(x-2)^2-4x+8 明天要交!

问题描述:

(x-2)^2-4x+8 明天要交!

(x-2)^2-4x+8
=x^2-4x+4-4x+8
=x^2-8x+12 (可用十字相乘法)
=(x^2-2x)-(6x-12)
=x(x-2)-6(x-2)
=(x-6)(x-2)

由题意:
(x-2)^2-4x+8
=(x-2)^2-4(x-2)
=(x-2)(x-2-4)
=(x-2)(x-6)