9x^2(x-1)^2-3(x^2-x)-56

问题描述:

9x^2(x-1)^2-3(x^2-x)-56

=9x^2(x-1)^2-3x(x-1)-56
=[3x(x-1)-8][3x(x-1)+7]
=(3x^2-3x-8)(3x^2-3x+7)