Chapter 2: Linear Equations

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.

    \[\begin{tabular}{|c|c|c|} \hline \begin{array}{ccc}&5& \\ \\ &\textbf{21}& \\ \\ 3&&6\end{array}& \begin{array}{ccc}&3& \\ \\ &\textbf{42}& \\ \\ 11&&9\end{array}& \begin{array}{ccc}&12& \\ \\ &\textbf{64}& \\ \\ 5&&X\end{array}\\ \hline \end{tabular}\]

Can you solve for X? Can you find any other possible solution?

<a class=”internal” href=”/intermediatealgebraberg/back-matter/answer-key-2-8/”>Answer Key 2.8

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