b/a= 6 if b is divisible by a, overline{ab}= (a + b)^2
Source: OLCOMA Costa Rica National Olympiad, Final Round, 2013 3.6
September 25, 2021
number theoryDigitsdivisible
Problem Statement
Let and be positive integers (of one or more digits) such that is divisible by , and if we write and , one after the other in this order, we get the number . Prove that .