4x^2-8x-12y-9y^2答案

问题描述:

4x^2-8x-12y-9y^2答案

4x^2-8x-12y-9y^2
=4x^2-8x+4-4-12y-9y^2
=(2x-2)^2-(2+3y)^2
=(2x-2+2+3y)(2x-2-2-3y)
=(2x+3y)(2x-3y-4)