(168) 1

Part of 1988 Tournament Of Towns

Problems(1)

TOT 168 1988 Spring J1 a^4 + b^4 + c^4 twice a perfect square

Source:

We are given that

a, b

c

are whole numbers (i.e. positive integers) . Prove that if

a = b + c

a^4 + b^4 + c^4

is double the square of a whole number.
(Folklore)

number theoryPerfect Square