Answer
{$-\frac{9}{2}$}
Work Step by Step
Factoring the equation and setting the factors equal to zero, we obtain:
$4x^{2}+36x+81=0$
$4x^{2}+18x+18x+81=0$
$2x(2x+9)+9(2x+9)=0$
$(2x+9)(2x+9)=0$
$(2x+9)=0$ or $(2x+9)=0$
$x=-\frac{9}{2}$ or $x=-\frac{9}{2}$
Therefore, the solution set is {$-\frac{9}{2}$}.
