The sum of the products of the elements of any row of a determinant $A$ with the corresponding co-factors is always equal to

The cofactor of the element $4$ in the determinant $\left| \begin{array}{cccc} 1 & 3 & 5 & 1 \\ 2 & 3 & 4 & 2 \\ 8 & 0 & 1 & 1 \\ 0 & 2 & 1 & 1 \end{array} \right|$ is

Let $A = [a_{ij}]_{n \times n}$ be a square matrix and let $c_{ij}$ be the cofactor of $a_{ij}$ in $A$. If $C = [c_{ij}]$,then which of the following is true?

If the cofactors of the elements $3$,$7$ and $6$ of the matrix $\begin{bmatrix} 1 & 2 & 3 \\ 4 & -1 & 7 \\ 2 & 4 & 6 \end{bmatrix}$ are $a$,$b$ and $c$ respectively,then $\begin{bmatrix} a & b & c \end{bmatrix} \begin{bmatrix} 1 \\ 4 \\ 2 \end{bmatrix} + \begin{bmatrix} a & b & c \end{bmatrix} \begin{bmatrix} 3 \\ 7 \\ 6 \end{bmatrix} = $

The cofactors of the elements of the first column of the matrix $A = \begin{bmatrix} 2 & 0 & -1 \\ 3 & 1 & 2 \\ -1 & 1 & 2 \end{bmatrix}$ are

Match the following elements of the matrix $A = \left[\begin{array}{ccc} 1 & -1 & 0 \\ 0 & 4 & 2 \\ 3 & -4 & 6 \end{array}\right]$ with their co-factors and choose the correct answer.

Element	Co-factor
$A$. $-1$	$(1)$ $-2$
$B$. $1$	$(2)$ $32$
$C$. $3$	$(3)$ $4$
$D$. $6$	$(4)$ $6$
	$(5)$ $-6$