用简便方法计算19×39又57分之55
问题描述:
用简便方法计算19×39又57分之55
答
19×39又57分之55
=19×(39+55/57)
=19×39+19×55/57
=741+55/3
=741+18+1/3
=759+1/3
=759又1/3