(1/10-1/11)+(1/11-1/12)+(1/12-1/13)+...(1/99-1/100)=?
问题描述:
(1/10-1/11)+(1/11-1/12)+(1/12-1/13)+...(1/99-1/100)=?
答
(1/10-1/11)+(1/11-1/12)+(1/12-1/13)+...(1/99-1/100)
=1/10-1/11+1/11-1/12+1/12-1/13+……+1/99-1/100
=1/10-1/100
=9/100