Question 163539
Call the number N.
{{{N+N^2=72}}}
{{{N^2+N-72=0}}}
{{{(N+9)(N-8)=0}}}
Two solutions.
{{{N+9=0}}}
{{{N=-9}}}
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{{{N-8=0}}}
{{{N=8}}}
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Check your answers. 
{{{-9+81=72}}}
{{{72=72}}}
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{{{8+64=72}}}
{{{72=72}}}
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Both answers lead to true statements.
Both answers are good answers.