计算:3(x²+2)-3(x+1)(x-1)

问题描述:

计算:3(x²+2)-3(x+1)(x-1)
赶紧的,谢了

3(x²+2)-3(x+1)(x-1)
=3x²+6-3(x²-1)
=3x²+6-3x²+3
=9