Question 144700
{{{x+x^2=72}}} Translate the word problem into the given equation



{{{x+x^2-72=0}}}  Subtract 72 from both sides. 



{{{x^2+x-72=0}}} Rearrange the terms




{{{(x+9)(x-8)=0}}} Factor the left side (note: if you need help with factoring, check out this <a href=http://www.algebra.com/algebra/homework/playground/change-this-name4450.solver>solver</a>)




Now set each factor equal to zero:

{{{x+9=0}}} or  {{{x-8=0}}} 


{{{x=-9}}} or  {{{x=8}}}    Now solve for x in each case



So our answers are

 {{{x=-9}}} or  {{{x=8}}} 




So {{{-9+81=72}}} or {{{8+64=72}}}