0.79×0.79×99=?求简便方法!

分类: 作业答案 • 2021-12-20 05:58:18

问题描述：

答

0.79×0.79×99
=(0.8-0.01)(0.8-0.01)(100-1)
=(0.8-0.01)²(100-1)
=(0.64-0.016+0.0001)(100-1)
=0.6241*100-0.6241*1
=62.41-0.6241
=61.7859