要从1/2,1/3,1/4,1/5...,1/49,1/50这49个分数中调出7个不同的数,使它们的和=1,把这7个分数

1=1/2+1/3+1/6=1/2+1/4+1/12+1/7+1/42=1/2+1/5+1/20+1/12+1/7+1/42
=1/3+1/6+1/5+1/7+1/20+1/42+1/12
3,5,6,7,12,20,42
具体方法就是用
1/n=1/(n+1)+1/(n*(n+1)) 不断的拆分