结果:3/13.
其实很微妙,易算
1/3-2/15=5/15-2/15=3/15=1/5,
1/5 3/35=7/35 3/35=10/35=2/7,
2/7-4/63=18/63-4/63=14/63=2/9,
2/9 5/99=22/99 5/99=27/99=3/11,
3/11-6/143=39/143-6/143=33/143=3/13.
结果:3/13.
其实很微妙,易算
1/3-2/15=5/15-2/15=3/15=1/5,
1/5 3/35=7/35 3/35=10/35=2/7,
2/7-4/63=18/63-4/63=14/63=2/9,
2/9 5/99=22/99 5/99=27/99=3/11,
3/11-6/143=39/143-6/143=33/143=3/13.