1=1/3+1/()+1/()+1/()+1/()+1/()+1/()+1/241/1*5+1/5*9+1/9*13+1/13*17+1/17*21第一题是填空题

Question

1=1/3+1/()+1/()+1/()+1/()+1/()+1/()+1/24
1/1*5+1/5*9+1/9*13+1/13*17+1/17*21
第一题是填空题

Answer 1

第一道是1/24、1/24、1/12、1/8、1/6、1/6
就是把14/25分成六个分数
第二道是
1/1*5+1/5*9+1/9*13+1/13*17+1/17*21
=(1/4)*（1-1/5）+(1/4)*（1/5-1/9)+(1/4)*(1/9-1/13)+(1/4)*(1/13-1/17)+(1/4)*(1/17-1/21)
=(1/4)*(1-1/21)
=5/21