7\9-18+3\4+5\18=( ) 怎样简便计算?
问题描述:
7\9-18+3\4+5\18=( ) 怎样简便计算?
答
7\9-18+3\4+5\18
=7/9+5/18+3/4-18
=19/18+3/4-18
=1/18+3/4-17
=2/36+27/36-17
=29/36-17
=-16又7/36