Linear Systems & Matrices · Hard problem

Multiply: $\begin{bmatrix} 1 & 2 & -1 \\ 0 & 3 & 1 \\ 2 & -1 & 4 \end{bmatrix}\begin{bmatrix} 2 & 0 & 1 \\ 1 & -1 & 3 \\ 0 & 2 & -2 \end{bmatrix}$.