What is the smallest positive integer that is the sum of two different pairs of integers raised to the 4th power? and how did you find it?
In other words what is the smallest x such that:
x = a^4 + b^4 = c^4 + d^4
(where x, a, b, c, and d are all different, non-zero, positive integers)?
Are you able to determine the answer without looking it up on the internet?