1/2+1/6+1/12+1/20+1/30+1/42+1/56 简算

分类: 作业答案 • 2021-12-17 20:49:19

问题描述：

答

1/2+1/6+1/12+1/20+1/30+1/42+1/56
=(1-1/2)+(1/2-1/3)+(1/3-1/4)+(1/4-1/5)+(1/5-1/6)+(1/6-1/7)+(1/7-1/8)
=1-1/8
=7/8