先化简再求值(x+3)(x-3)-6(x-6)其中x=2

问题描述:

先化简再求值(x+3)(x-3)-6(x-6)其中x=2

(x+3)(x-3)-6(x-6)
=x²-9-6x+36
=x²-6x+27
=4-12+27
=19