Question 111372


{{{x^2-9=0}}}


{{{(x-3)(x+3)=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-3=0}}} or {{{x+3=0}}}


{{{x=3}}} or {{{x=-3}}}  Now solve for x in each case



So our solutions are {{{x=3}}} or {{{x=-3}}}



Notice if we graph {{{y=x^2-9}}} we get


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


and we can see that the graph has roots at {{{x=3}}} and {{{x=-3}}}, so this verifies our answer.