7.2×14.5+17×2.8这道题怎么简便计算?
问题描述:
7.2×14.5+17×2.8这道题怎么简便计算?
答
7.2×14.5+17×2.8
=(10-2.8)×14.5+17×2.8
=145+(17-14.5)×2.8
=145+10/4×2.8
=145+7
=152