x^2 + y^2 - 5xy + 5 = 0
Source: Vietnam TST 1992 for the 33nd IMO, problem 5
June 25, 2005
quadraticsinvariantsymmetrynumber theory unsolvednumber theory
Problem Statement
Find all pair of positive integers satisfying the equation
Source: Vietnam TST 1992 for the 33nd IMO, problem 5