## Compute the Determinant of a Magic Square

## Problem 718

Let

\[

A=

\begin{bmatrix}

8 & 1 & 6 \\

3 & 5 & 7 \\

4 & 9 & 2

\end{bmatrix}

.

\]
Notice that $A$ contains every integer from $1$ to $9$ and that the sums of each row, column, and diagonal of $A$ are equal. Such a grid is sometimes called a magic square.

Compute the determinant of $A$.

Add to solve later