Answer
$$ f'(x)= \frac{27}{2}x^{3/2}+\frac{2}{x^2}.$$
Work Step by Step
First, we simplify $ f(x) $ as follows
$$ f(x)=\frac{9x^{5/2}-2}{x}=9x^{3/2}-2x^{-1}.$$
Now, the derivative is given by
$$ f'(x)=9(3/2)x^{1/2}+2x^{-2}=\frac{27}{2}x^{3/2}+\frac{2}{x^2}.$$