计算 2(x²-x+1)-(-2x+3x²)+(1-x)

问题描述:

计算 2(x²-x+1)-(-2x+3x²)+(1-x)

2(x^2-x+1)-(-2x+3x^2)+(1-x)
=2x^2-2x+2+2x-3x^2+1-x
=-x^2-x+3