Question 119194
{{{x^2+6x+9=49}}} Start with the given equation



{{{x^2+6x+9-49=0}}}  Subtract 49 from both sides. 



{{{x^2+6x-40=0}}} Combine like terms



{{{(x+10)(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+10=0}}} or  {{{x-4=0}}} 


{{{x=-10}}} or  {{{x=4}}}    Now solve for x in each case



So our answer is 

 {{{x=-10}}} or  {{{x=4}}} 



Notice if we graph {{{y=x^2+6x-40}}} we can see that the roots are {{{x=-10}}} and  {{{x=4}}} . So this visually verifies our answer.



{{{ graph(500,500,-12,10,-10,10,0, x^2+6x-40) }}}



So the answer is C)