Question 175091
Let the number = n.
{{{n^2+n = 56}}} Subtract 56 from both sides.
{{{n^2+n-56 = 0}}} Solve by factoring.
{{{(n-7)(n+8) = 0}}} 
{{{n-7 = 0}}} or {{{n+8 = 0}}} so...
{{{highlight(n = 7)}}} or {{{highlight(n = -8)}}}
There are two answers to this problem: 7 and -8
Check:
{{{7^2+7 = 49+7}}} = {{{56}}}
{{{(-8)^2 + (-8) = 64 + (-8)}}} = {{{56}}}