(-1/2)+(-2/5)+(+3/2)+(18/5)+(39/5)怎么简算

问题描述:

(-1/2)+(-2/5)+(+3/2)+(18/5)+(39/5)怎么简算

(-1/2)+(-2/5)+(+3/2)+(18/5)+(39/5)
=(-1/2+3/2)+(-2/5+18/5+39/5)
=2/2+55/5
=1+11
=12