Question 118177

{{{x^2-9x=-20}}} Start with the given equation



{{{x^2-9x+20=0}}}  Add 20 to both sides. 


{{{(x-5)(x-4)=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-5=0}}} or  {{{x-4=0}}} 


{{{x=5}}} or  {{{x=4}}}    Now solve for x in each case



So our answer is 

 {{{x=5}}} or  {{{x=4}}} 



Notice if we graph {{{y=x^2-9x+20}}} we can see that the roots are {{{x=5}}} and  {{{x=4}}} . So this visually verifies our answer.



{{{ graph(500,500,-10,10,-10,10,0, x^2-9x+20) }}}