57*55/56+27*27/28的简便算法.
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:2024/08/04 05:37:53
57*55/56+27*27/28的简便算法.
![57*55/56+27*27/28的简便算法.](/uploads/image/z/1706941-37-1.jpg?t=57%2A55%2F56%2B27%2A27%2F28%E7%9A%84%E7%AE%80%E4%BE%BF%E7%AE%97%E6%B3%95.)
57*55/56+27*27/28
=[56+1]*55/56+(28-1)27/28
=56*55/56+55/56+28*27/28-27/28
=55+55/56+27-27/28
=82+1/56
=82又1/56
=[56+1]*55/56+(28-1)27/28
=56*55/56+55/56+28*27/28-27/28
=55+55/56+27-27/28
=82+1/56
=82又1/56