Answer
$\frac{27-9\sqrt{2x}}{9-2x}$.
Work Step by Step
The given expression is
$=\frac{9}{3+\sqrt{2x}}$
Multiply and divide by the conjugate of the denominator.
$=\frac{9}{3+\sqrt{2x}}\cdot \frac{3-\sqrt{2x}}{3-\sqrt{2x}}$
Use distributive property and the FOIL method.
$=\frac{27-9\sqrt{2x}}{9-3\sqrt{2x}+3\sqrt{2x}+(\sqrt{2x})(-\sqrt{2x})}$
Simplify.
$=\frac{27-9\sqrt{2x}}{9-2x}$.