5. (15 pts) Let

$$A = \begin{pmatrix} 3 & 1 & 2 \\ 0 & 3 & 0 \\ 0 & 0 & 3 \end{pmatrix}.$$

Find a Jordan canonical form $J$ of $A$ and an invertible matrix $Q$ such that $J = Q^{-1}AQ$.