$\let A \in M_{n \times m}$, to compute a minor [[Matrix]] $c_{r, q} \in M_{ (n-1) \times (m-1) }$ such that $c_{r,q}$ is a sub matrix with the row $r$ column $q$ removed. ** >[!example] $3\times 3$ Matrix Example > $ \huge \let A \in M_{3\times 3}$ > $\huge a_{1, 3} = \mat { & & \\ a_{21} & a_{22} & \\ a_{31} & a_{32} & \\ } $