题目

50.9*1.9*1.9-1.8简便计算

提问时间：2021-01-23

答案

50.9*1.9*1.9-1.8
=50.9*(2-0.1)*(2-0.1)-1.8
=50.9*(4-0.2-0.2+0.01)-1.8
=(50+0.9)*3.61-1.8
=180.5+3.249-1.8
=181.949