Question
If $a_1, a_2, a_3, \ldots, a_9$ are in A.P., then the value of $\begin{vmatrix} a_1 & a_2 & a_3 \\ a_4 & a_5 & a_6 \\ a_7 & a_8 & a_9 \end{vmatrix}$ is?
If $a_1, a_2, a_3, \ldots, a_9$ are in A.P., then the value of $\begin{vmatrix} a_1 & a_2 & a_3 \\ a_4 & a_5 & a_6 \\ a_7 & a_8 & a_9 \end{vmatrix}$ is?