85×99十85怎么简便算
问题描述:
85×99十85怎么简便算
答
85x99+85=85x(99+1)=85x100=8500脱式85x99+85=85x(100-1)+85=85x100-85x1+85=8500-85+85=850075×124-75×24呢原式=75x(100+24)-75x24=75x100+75x24-75x24=75x100=7500