12. Express $x^{5}-3 x+2$ in terms of the powers of $x^{2}-x-1$.

Use $x^{2}-x-1$'s powers to represent $x^{5}-3 x+2$.
$\begin{array}{l}(x+2)\left(x^{2}-x-1\right)^{2}+(5 x+2)\left(x^{2}-x-1\right) \\ +2 x+2\end{array}$