Minors
Minors[m] gives the minors of a matrix m. Minors[m, k] gives the kth minors.
Examples
Minors of a matrix:
Minors[{{a, b}, {c, d}}]
(* {{a d - b c}} *)2x2 minors of a 3x3 matrix:
Minors[{{1, 2, 3}, {4, 5, 6}, {7, 8, 9}}, 2]
(* {{-3, -6, -3}, {-6, -12, -6}, {-3, -6, -3}} *)Please visit the official Wolfram Language Reference for more details.