1996 AIME Problem 1

In a magic square, the sum of the three entries in any row, column, or diagonal is the same value. The figure shows four of the entries of a magic square. Find x.

\begin{array}{|c|c|c|} \hline x & 19 & 96 \\ \hline 1 & & \\ \hline & & \\ \hline \end{array}