Question 64
Determine all integer solutions of the equation
$$
(x - 1) \cdot x + (x + 1) + (y - 1) \cdot y + (y + 1) = 24 - 9 \cdot xy.
$$
$$
(x - 1) \cdot x + (x + 1) + (y - 1) \cdot y + (y + 1) = 24 - 9 \cdot xy.
$$
MathNet 2012 Question 64
Math Olympiad Vault · MathNet 2012