3(2x-1)(x+6)-5(x-3)(x+6)

问题描述:

3(2x-1)(x+6)-5(x-3)(x+6)

3(2x-1)(x+6)-5(x-3)(x+6)
=3(2x2+12x-x-6)-5(x2+6x-3x-18)
=6x2+33x-18-5x2-15x+90
=x2+18x+72