3(2x-1)(x+6)-5(x-3)(x+6)
问题描述:
3(2x-1)(x+6)-5(x-3)(x+6)
答
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