MathDB
Set in which each product is a sum

Source: 2023 Israel National Olympiad P6

December 16, 2022
algebraSets

Problem Statement

Determine if there exists a set SS of 57835783 different real numbers with the following property: For every a,bSa,b\in S (not necessarily distinct) there are cdc\neq d in SS so that ab=c+da\cdot b=c+d.