28.
Directions (Qn. 28-30): Consider the following for the next three (03) items that follow:
Let \( \Delta \) be the determinant of a matrix \( A \), where \( A = \begin{bmatrix} a_{11} & a_{12} & a_{13} \\ a_{21} & a_{22} & a_{23} \\ a_{31} & a_{32} & a_{33} \end{bmatrix} \) and \( C_{11}, C_{12}, C_{13} \) be the cofactors of \( a_{11}, a_{12}, a_{13} \) respectively.
What is the value of \( a_{11}C_{11} + a_{12}C_{12} + a_{13}C_{13} \)?