巧算7.2*61.3+73.8*2.8
问题描述:
巧算7.2*61.3+73.8*2.8
快
答
7.2*61.3+73.8*2.8
=7.2*73.8+73.8*2.8-12.5*7.2
=738-12.5*4*1.8
=738-90
=648