[x+2][x+3]减去[x+6][x减1]怎么算.
问题描述:
[x+2][x+3]减去[x+6][x减1]怎么算.
答
(x+2)(x+3)-(x+6)(x-1)
=x²+5x+6-(x²+5x-6)
=12