2分之7*8分之5-2分之3/5分之8怎么简便
问题描述:
2分之7*8分之5-2分之3/5分之8怎么简便
答
7/2*5/8-(3/2)/(8/5)
=7/2*5/8-(3/2)*(5/8)
=5/8*(7/2-3/2)
=5/8*2
=5/4