(-9)-(-2)+(-7)-(+5)-(-4)写成省略加号形式到底该怎样写

问题描述:

(-9)-(-2)+(-7)-(+5)-(-4)写成省略加号形式
到底该怎样写

(-9)-(-2)-7-5-(-4)

(-9)-(-2)+(-7)-(+5)-(-4)
=-9+2-7-5+4