29用简便运算怎么算?
28*28/29用简便运算怎么算?
28/29×28……………………变一变,就简便。把28变成(29-1) =28/29×(29-1)……………乘法分配律 =28/29×29-28/29×1 =28-28/29 =27又1/29 28/29×28……………………变一变,就简便。把28/29变成(1-1/29) =(1-1/29)×28……………乘法分配律 =28-28/29 =27又1/29(真心帮助你,愿你给个好评哟^_^)
28/29×28……………………变一变,就简便。把28变成(29-1) =28/29×(29-1)……………乘法分配律 =28/29×29-28/29×1 =28-28/29 =27又1/29
答:571-399+299-101 = 570+1-400+1+300-1-100-1 = 570详情>>
答:详情>>