If $\Delta=\left|\begin{array}{lll}a_{11} & a_{12} & a_{13} \\ a_{21} & a_{22} & a_{23} \\ a_{31} & a_{32} & a_{33}\end{array}\right|$ and $A_{i j}$ is co-factor of $a_{i j}$, then value of $\Delta$ is equal to
Answer & explanation
Correct answer: option 4
The sum of products of corresponding teams with their corresponding co-factors gives the value of determinant either along a row/column
$\Delta=a_{11} A_{11}+a_{21} A_{21}+a_{31} A_{31}$