用简便方法计算下列各题:7/18/5+1/18*1/5

问题描述:

用简便方法计算下列各题:7/18/5+1/18*1/5

7/18/5+1/18*1/5
=(7/18+1/18)×1/5
=4/9×1/5
=4/45