MathDB
Perfect square

Source: French TST 2005 - pb 1

May 26, 2005
number theory unsolvednumber theory

Problem Statement

Let xx, yy be two positive integers such that 3x2+x=4y2+y\displaystyle 3x^2+x=4y^2+y. Prove that xāˆ’yx-y is a perfect square.