七上(-21/4)-(+103/12)-(+12/7)-(+15/4)-(+2/7)简便运算

问题描述:

七上(-21/4)-(+103/12)-(+12/7)-(+15/4)-(+2/7)简便运算
简便运算(要过程!)

(-21/4)-(+103/12)-(+12/7)-(+15/4)-(+2/7)
=(-21/4-15/4)-103/12-(12/7+2/7)
=-9-103/12-2
=-11-103/12
=235/12