Skip to content / Đến nội dung
ThichHocToan.com

MathNet 2004 — Part 02 Question 30

Math Olympiad Vault · MathNet 2004 — Part 02

Question 30

How many pairs of positive integers $ (x, y) $ verify the equation
$$
x^{2}+y^{2}-2004 x-2004 y+2 x y-2005=0 ?
$$

Note: if $x \neq y$, the $(x, y)$ and $(y, x)$ pairs are to be considered different.