Determinants

The determinant of the 2×2 matrix [[a, b], [c, d]] is:

If $\det(A) = 0$, the matrix A is:

Evaluate the determinant $\det(A)$ for $A = \begin{pmatrix} -1 & 3 & -1 \\ 3 & 1 & 2 \\ -3 & 1 & 1 \end{pmatrix}$.