如何证明:1/n(n1)=1/n-1/n1

Question

如何证明:1/n(n 1)=1/n-1/n 1

Answer 1

求证1/n(n+1)=1/n-1/n+1
1/n-1/n+1=(n+1-n)/n(n+1)
=1/n(n+1)