Question 125006
{{{n*(n + 1) = 72}}}
{{{n^2 + n - 72 = 0}}}
{{{(n - 8)(n + 9)}}}
The solutions are 
{{{n = 8}}}
{{{n = -9}}}
I choose {{{n = 8}}} since I want positive numbers
{{{n = 8}}}
{{{n + 1 = 9}}}
{{{8*9 = 72}}} answer