For what values of $x$, $\begin{bmatrix} 1 & 2 & 1 \end{bmatrix} \begin{bmatrix} 1 & 2 & 0 \\ 2 & 0 & 1 \\ 1 & 0 & 2 \end{bmatrix} \begin{bmatrix} 0 \\ 2 \\ x \end{bmatrix}$ = 0 ?

Question

$\begin{array}{1 1} x=2 \\ x=1 \\ x=-1 \\ x=3 \end{array}$