(x-1)(x-2)+3x(x+3)-4(x-2)(x+2)

问题描述:

(x-1)(x-2)+3x(x+3)-4(x-2)(x+2)

(x-1)(x-2)+3x(x+3)-4(x-2)(x+2)
展开得
=x^2-3x+2+3x^2+9x-4x^2+16
=6x+18