0.8(2.5+1.25)0.4怎么巧算

分类: 作业答案 • 2021-12-01 17:00:42

问题描述：

0.8*(2.5+1.25)*0.4怎么巧算

答

0.8*(2.5+1.25)*0.4
=0.8*(2.5*0.4+1.25*0.4)
=0.8*(1+0.5)
=0.8+0.4
=1.2
或者
0.8*(2.5+1.25)*0.4
=0.8*(2.5*0.4)+(0.8*1.25)*0.4
=0.8+0.4
=1.2

0.8*(2.5+1.25)*0.4怎么巧算