1/2+1/6+1/12+1/20+.1/(2005*2006)=?

分类: 作业答案 • 2022-01-09 18:01:45

问题描述：

答

1/2+1/6+1/12+1/20+.1/(2005*2006)
=1-1/2+1/2-1/3+1/3-1/4+……+1/2005-1/2006
=1-1/2006
=2005/2006