用简便算法计算19*39又55/57
来源:学生作业帮 编辑:搜搜做题作业网作业帮 分类:数学作业 时间:2024/07/11 23:26:40
用简便算法计算19*39又55/57
![用简便算法计算19*39又55/57](/uploads/image/z/9429218-26-8.jpg?t=%E7%94%A8%E7%AE%80%E4%BE%BF%E7%AE%97%E6%B3%95%E8%AE%A1%E7%AE%9719%2A39%E5%8F%8855%2F57)
原式=((20-1)*(40-1))*55/(3*19)
=(800-20-40+1)/((4/3)-(7/19))
=741/((4/3)-(7/19))
=(741*4/3)-(741*7/19)
=247*4-39*7
=988-273=715
=(800-20-40+1)/((4/3)-(7/19))
=741/((4/3)-(7/19))
=(741*4/3)-(741*7/19)
=247*4-39*7
=988-273=715