78*78/79的简便计算

分类: 作业答案 • 2023-01-05 01:18:12

问题描述：

78*78/79的简便计算

答

78*78/79
=(79-1)(79-1)/79
=79^2-2*79+1/79
=79-2+1/79
=77+1/79
=77又1/79