Suppose the vectors $x_1, x_2$ and $x_3$ are the solutions of the system of linear equations, $A x=b$ when the vector $b$ on the right side is equal to $b_1, b_2$ and $b_3$ respectively. If $x_1=\left[\begin{array}{l}1 \\ 1 \\ 1\end{array}\right], x_2=\left[\begin{array}{l}0 \\ 2 \\ 1\end{array}\right] x_3=\left[\begin{array}{l}0 \\ 0 \\ 1\end{array}\right] b_1=\left[\begin{array}{l}1 \\ 0 \\ 0\end{array}\right], b_2=\left[\begin{array}{l}0 \\ 2 \\ 0\end{array}\right]$ and $b_3=\left[\begin{array}{l}0 \\ 0 \\ 2\end{array}\right]$, then the determinant of $A$ is equal to