12.8X34.5+12.8X12.3+46.8X87.2=?
问题描述:
12.8X34.5+12.8X12.3+46.8X87.2=?
简便运算!
答
12.8*(34.5+12.3)+46.8*87.2
=12.8*46.8+46.8*87.2
=(12.8+87.2)*46.8
=100*46.8
=4680
对吗?