320x(1.25+2.5+0.5)巧算

分类: 作业答案 • 2022-06-19 22:14:27

问题描述：

答

320x(1.25+2.5+0.5)
=320x1.25+320x2.5+320x0.5
=320x5/4+320x5/2+320x1/2
=400+800+160
=1360