1/(1*2*3)+1/(2*3*4)+1/(3*4*5)+1/(4*5*6)+.+1/(24*25*26)=?
1个回答
展开全部
1/(1*2*3)+1/(2*3*4)+1/(3*4*5)+1/(4*5*6)+.+1/(24*25*26)
=1/2*(1/1*2-1/2*3)+1/2*(1/2*3-1/3*4)+……+1/2*(1/24*25-1/25*26)
=1/2*(1/1*2-1/2*3+1/2*3-1/3*4+……+1/24*25-1/25*26)
=1/2*(1/1*2-1/25*26)
=1/2*(1/2-1/650)
=81/325
=1/2*(1/1*2-1/2*3)+1/2*(1/2*3-1/3*4)+……+1/2*(1/24*25-1/25*26)
=1/2*(1/1*2-1/2*3+1/2*3-1/3*4+……+1/24*25-1/25*26)
=1/2*(1/1*2-1/25*26)
=1/2*(1/2-1/650)
=81/325
已赞过
已踩过<
评论
收起
你对这个回答的评价是？
推荐律师服务：
若未解决您的问题，请您详细描述您的问题，通过百度律临进行免费专业咨询
