2.31×0.78-1.37×78/10简便方法

分类: 作业答案 • 2022-04-03 19:26:44

问题描述：

答

2.31×0.78-1.37×78/10
=0.231×7.8-1.37×7.8
=（0.231-1.37）×7.8
=-1.039×7.8
=-7.8-0.04×7.8+0.0078
=-7.8-0.312+0.0078
=-8.1042