Turkish NMO First Round - 2012 Problem - 22 {Number Theory}
Source:
July 1, 2012
symmetry
Problem Statement
How many integer pairs (m,n) are there satisfying 4mn(m+n−1)=(m2+1)(n2+1)?<spanclass=′latex−bold′>(A)</span>5<spanclass=′latex−bold′>(B)</span>4<spanclass=′latex−bold′>(C)</span>3<spanclass=′latex−bold′>(D)</span>2<spanclass=′latex−bold′>(E)</span>1