3(x-1)(x-2)-3x(x+3)(全过程)
问题描述:
3(x-1)(x-2)-3x(x+3)(全过程)
答
3(x-1)(x-2)-3x(x+3)
=3(x^2-3x+2)-3x(x+3)
=3x^2-9x+6-3x^2-9x
=6-18x