Stuck on a question in a test paper, my book touches this topic but in a different form.

Show that these equations are consistent and find their general solution:

$\displaystyle

\begin{bmatrix}

2&1&1\\

1&2&1\\

2&1&1

\end{bmatrix}

\begin{bmatrix}

x\\y\\z

\end{bmatrix}

=\begin{bmatrix}

2\\3\\2

\end{bmatrix}

$

Pretty sure I take the determinant.. of something.

Thanks