By Fermat Last theorem, I don't know if that's been discussed.
Find all positive integers $x,y,z$ such $$x^3+y^3=3z^3$$
By Fermat Last theorem, I don't know if that's been discussed.
Find all positive integers $x,y,z$ such $$x^3+y^3=3z^3$$
This is proved in Hardy and Wright, (An introduction to the theory of numbers), Theorem 232. (After proving first the classical $x^3+y^3=z^3$, the notation and methods are ready, to prove this case in a quite similar way.)