3(x-2y)(x+2y)-9(2y-x)^2

问题描述:

3(x-2y)(x+2y)-9(2y-x)^2
分解因式

3(x-2y)(x+2y)-9(2y-x)^2
=(x-2y)(3x+6y)-(x-2y)(9x-18y)
=(x-2y)(3x+6y-9x+18y)
=(x-2y)(24y-6x)
=6(x-2y)(4y-x)