IMO 2018 Shortlist N5

Four positive integers x, y, z, and t satisfy the relations xy ´ zt “ x y “ z t. Is it possible that both xy and zt are ...

IMO 2018 Shortlist N5

Category: Number Theory

Problem

Four positive integers x, y, z, and t satisfy the relations xy ´ zt “ x y “ z t. Is it possible that both xy and zt are perfe t squares? (Russia)