11. Let $\mathrm{f}$ be a function defined on non-zero real numbers such that
$$
\frac{27 \mathrm{f}(-x)}{x}-x^{2} \mathrm{f}\left(\frac{1}{x}\right)=-2 x^{2},
$$
for all $x \neq 0$. Find $\mathrm{f}(3)$.