发布网友
共2个回答
热心网友
5/6+(7/15-9/20)
=5/6+7/15-9/20
=50/60+28/60-27/60(通分,最小公倍数是60)
=51/60
望采纳!
热心网友
5/6+(7/15-9/20)
=5/6+1/60
=49/60