15 2.8 The Mystery X Puzzle
The centre number of each square is found by using the order of operations on the numbers that surround it. The challenge is to solve for the variable \(X.\)
$$
\begin{array}{|c|c|c|}
\hline
\begin{array}{ccc}
& 5 & \\
& \mathbf{21} & \\
3 & & 6
\end{array} &
\begin{array}{ccc}
& 3 & \\
& \mathbf{42} & \\
11 & & 9
\end{array} &
\begin{array}{ccc}
& 12 & \\
& \mathbf{64} & \\
5 & & X
\end{array} \\
\hline
\end{array}
$$
Can you solve for \(X\)? Can you find any other possible solution?
