### Submatrix of a given ~~matrix~~matrix by deleting some rows and columns(For my case 2 rows and columns).

How to obtain submatrix of a given matrix of any size? Actually I have a matrix A of order $n\times n$ with all non-singlular submatrices of order ~~$n-1$ and ~~$n-2$. Now I need another matrix B whose (i,j)th entry is
~~$\frac{det A(i,j)}{det A(i)}$, ~~$det A(i,j)$, where $det A(i,j)$ denote the determinant of the sub matrix of A formed by deleting $i^{th}$ and $j^{th}$ rows and ~~columns, and ~~columns. ~~$det A(i)$ denote the determinant of the sub matrix of A formed by deleting $i^{th}$ row and column. ~~I'm unable to generate the submatrices $A(i,j)$ for every ~~element.~~element at a time.