Find all pairs of positive integers $(x, y)$ so that $$(xy - 6)^2 | x^2 + y^2$$
Problem
Source: http://drive.google.com/file/d/1OzcOBEZZMCgCeiDLLjyRbK0KkwN4207F/view
Tags: number theory, IMOC
Source: http://drive.google.com/file/d/1OzcOBEZZMCgCeiDLLjyRbK0KkwN4207F/view
Tags: number theory, IMOC
Find all pairs of positive integers $(x, y)$ so that $$(xy - 6)^2 | x^2 + y^2$$