Question 129911


{{{g^2-4g-45=0}}} Start with the given equation


{{{(g-9)(g+5)=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:

{{{g-9=0}}} or  {{{g+5=0}}} 


{{{g=9}}} or  {{{g=-5}}}    Now solve for g in each case



So our answer is 

 {{{g=9}}} or  {{{g=-5}}} 



Notice if we graph {{{y=x^2-4x-45}}}  (just replace g with x)  we can see that the roots are {{{x=9}}} and  {{{x=-5}}} . So this visually verifies our answer.



{{{ graph(500,500,-10,10,-10,10,0, x^2-4x-45) }}}