4x^5-7 and 4x^13-7 being perfect squares
Source: German DEMO 2008, grade 11-13, round 4, problem 6
May 22, 2008
number theory proposednumber theory
Problem Statement
Find all real numbers such that 4x^5 \minus{} 7 and 4x^{13} \minus{} 7 are both perfect squares.