l1/3-1/2l+l1/4-1/3l+l1/5-1/4l+……+l1/2012-1/2011l 怎么算

分类: 作业答案 • 2021-12-31 11:55:50

问题描述：

答

l1/3-1/2l+l1/4-1/3l+l1/5-1/4l+……+l1/2012-1/2011l
=1/2-1/3+1/3-1/4+1/4-1/5+……+1/2011-1/2012
=1-1/2012
=2011/2012