%Derpy but works
\begin{align}
    \left[\left\vphantom{|}
    \begin{matrix}
    2 & 1 & 0\\
    1 & 2 & 1\\
    0 & 1 & 2\
    end{matrix}
    \,\right|\,
    \begin{matrix}
    1 & 0 & 0\\
    0 & 1 & 0\\
    0 & 0 & 1
    \end{matrix}
    \right]
\end{align}