Question

Calculați 1/n - 1/n+1.

Answer 1

= (n+1-n) / [ n(n+1) ] = 1 / [ n(n+1) ]

Answer 2

$\frac{1}{n}-\frac{1}{n+1}=(dupa\;amplificari)=\frac{n+1-n}{n(n+1)}=\frac{1}{n(n+1)}$