Respuesta :
A. n(n+1), just factor out a "n" form the equation and you are left in parenthesis.
n^2 + n
if you divide the whole thing by n
you will see that n^2/n =n
and n/n=1
therefore n(n+1)
if you divide the whole thing by n
you will see that n^2/n =n
and n/n=1
therefore n(n+1)