\frac{2\left(\frac{9}{4}x-9\right)}{9}
\frac{9}{4}x\::\quad \frac{9x}{4}
\frac{2\left(\frac{9x}{4}-9\right)}{9}
\frac{9x-36}{4}\::\quad \frac{9x-36}{2}
\frac{9x-36}{4}
\frac{\left(9x-36\right)\cdot \:2}{4}
\frac{9x-36}{2}
\frac{\frac{9x-36}{2}}{9}
\frac{9x-36}{18}
Your answer is \frac{x}{2}-2