合并同类项:2x2+1-3x+7-3x2+5x.

问题描述:

合并同类项:2x2+1-3x+7-3x2+5x.

2x2+1-3x+7-3x2+5x
=(2-3)x2+(-3+5)x+8,
=-x2+2x+8.