80.5乘2.8加143.5 怎样简便计算

分类: 作业答案 • 2022-01-15 23:48:19

问题描述：

答

=80.5X（3-0.2）+143.5
=80.5*3-80.5*0.2+143.5
=241.5-16.1+143.5
=241.5+143.5-16.1
=385-16.1
=368.9