+15与+7,-11,+3,+12,+5,-8,-14怎么计算

问题描述:

+15与+7,-11,+3,+12,+5,-8,-14怎么计算

15+7-11+3+12+5-8-14
=(15+5+7+3+12)-(14+8)-11
=42-22-11
=20-11
=9