MathDB
Perfect Square

Source: Switzerland Math Olympiad, Final round 2014, P2

June 2, 2014
number theoryleast common multiplenumber theory proposed

Problem Statement

Let a,bNa,b\in\mathbb{N} such that : ab(ab)a3+b3+ab ab(a-b)\mid a^3+b^3+ab Then show that lcm(a,b)\operatorname{lcm}(a,b) is a perfect square.