已知1/6=1/2-1/3,1/12=1/3-1/4,1/20=1/4-1/5,那么1/6+1/12+1/20+1/30+1/42+1/56=?

分类: 作业答案 • 2022-01-24 22:44:50

问题描述：

答

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