Henry Ernest Dudeney/Modern Puzzles/173 - Difference Squares/Solution

by : $173$

 * Difference Squares

Solution
These may be the only ones:


 * $\begin{array}{|c|c|c|}

\hline 2 & 1 & 4 \\ \hline 3 & 5 & 7 \\ \hline 6 & 9 & 8 \\ \hline \end{array} \qquad \begin{array}{|c|c|c|} \hline 8 & 1 & 4 \\ \hline 3 & 5 & 7 \\ \hline 6 & 9 & 2 \\ \hline \end{array} \qquad \begin{array}{|c|c|c|} \hline 2 & 1 & 6 \\ \hline 3 & 5 & 7 \\ \hline 4 & 9 & 8 \\ \hline \end{array}$

The difference throughout is $5$.