The Determinant(A) command computes the determinant of the square Matrix A.

$\mathrm{with}\left(\mathrm{Student}\left[\mathrm{LinearAlgebra}\right]\right)\:$

$A≔⟨⟨1\,2\,3⟩\left|⟨4\,5\,6⟩\right|⟨7\,8\,2⟩⟩$

$A≔\left[\begin{array}{ccc}1& 4& 7\\ 2& 5& 8\\ 3& 6& 2\end{array}\right]$

$\mathrm{Determinant}\left(A\right)$

$21$

$B≔⟨⟨1-x\,2⟩|⟨3\,-1-x⟩⟩$

$B≔\left[\begin{array}{cc}1-x& 3\\ 2& -1-x\end{array}\right]$

$\mathrm{Determinant}\left(B\right)$

$x^2-7$