Let $\displaystyle A(a_{i,j})$ be a $\displaystyle 3\times 3$ matrix, such that $\displaystyle a_{i,j}\in \left \{ 1,2,3,...9 \right \}$ and all matrix entries are distinct (no repetitions).

I need to find such A with a maximum determinant.

I can really use some guidance here.

thanks in advanced!