Answer
{$-3,9$}
Work Step by Step
Using the rules for the factoring of trinomials, we obtain:
$x(x-6)=27$
$x^{2}-6x-27=0$
$x^{2}+3x-9x-27=0$
$x(x+3)-9(x+3)=0$
$(x+3)(x-9)=0$
$(x+3)=0$ and $(x-9)=0$
$x=-3$ and $x=9$
Therefore, the solution set is {$-3,9$}.