6/13乘5/12加7/12乘5/13简便方法计算
问题描述：
6/13乘5/12加7/12乘5/13简便方法计算
答
6/13×5/12+7/12×5/13
= (6×5+7×5)/(13×12)
= [5×(6+7)]/(13×12)
= (5×13)/(13×12)
= 5/12