简便计算:[(-7/5)+(-7/3)-(-7/4)]/(-7)

问题描述:

简便计算:[(-7/5)+(-7/3)-(-7/4)]/(-7)

[(-7/5)+(-7/3)-(-7/4)]/(-7)
=[(1/5)+(1/3)-(1/4)][-7]/(-7)
=1/5+1/3-1/4
=(12+20-15)/60
=17/60