先化简,再求值:(x+2)(x-3)+3(x-1)(x-1)-(2x-1)(2x+3),其中x=负2,

题目

先化简,再求值:(x+2)(x-3)+3(x-1)(x-1)-(2x-1)(2x+3),其中x=负2,

答案

(x+2)(x-3)+3(x-1)(x-1)-(2x-1)(2x+3),
=x^2-x-6+3(x^2-2x+1)-(4x^2+4x-3)
=x^2-x-6+3x^2-6x+3-4x^2-4x+3
=-2x
=-2*(-2)
=4