来自贾明华的问题
【1/3+1/15+1/35+1/63+1/99=?】
1/3+1/15+1/35+1/63+1/99=?
1回答
2020-03-03 07:14
【1/3+1/15+1/35+1/63+1/99=?】
1/3+1/15+1/35+1/63+1/99=?
1/3+1/15+1/35+1/63+1/99
=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)
=1/2×10/11
=5/111/3+1/15+1/35+1/63+1/99
=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)
=1/2×10/11
1/3+1/15+1/35+1/63+1/99
=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)
=1/2×10/11
=5/11=5/111/3+1/15+1/35+1/63+1/99
=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)
=1/2×10/11
1/3+1/15+1/35+1/63+1/99
=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)
=1/2×10/11
=5/11=5/11