1/1x3+1/3x5+1/5x7+1/7x9+1/9x11=?

分类: 作业答案 • 2023-01-07 11:55:18

问题描述：

答

=(1/2)×(1-1/3)+(1/2)×(1/3-1/5)+(1/2)×(1/5-1/7)+(1/2)×(1/7-1/9)+(1/2)×(1/9-1/11)
=(1/2)×(1-1/3+1/3-1/5+1/5-1/7+1/7-1/9+1/9-1/11)
=(1/2)×(1-1/11)
=5/11