1/15+1/35+1/63+1/99+1/143
来源：学生作业帮助网 编辑：六六作业网 时间：2024/12/22 14:20:50
1/15+1/35+1/63+1/99+1/1431/15+1/35+1/63+1/99+1/1431/15+1/35+1/63+1/99+1/1431/15+1/35+1/63+1/99+1/143
1/15+1/35+1/63+1/99+1/143
1/15+1/35+1/63+1/99+1/143
1/15+1/35+1/63+1/99+1/143
1/15+1/35+1/63+1/99+1/143
=[1/3-1/5+1/5-1/7+1/7-1/9+1/9-1/11+1/11-1/13]/2
=[1/3-1/13]/2
=5/39
你好
原式=1/3*1/5+1/5*1/7+1/7*1/9+1/9*1/11+1/11*1/13
=[(1/3-1/5)+(1/5-1/7)+(1/7-1/9)+(1/9-1/11)+(1/11-1/13)]/2
=(1/3-1/13)/2
=10/39/2
=5/39