I think I posted this in the wrong forum before. Let's try again. I need to prove that the equation [itex]x^3 + y^3 = 3z^3[/itex] has no integer solutions. I can do it easily for all cases except where z has a factor of 3, in which case I don't know what to do. I am assuming the 3 in front of the z term is supposed to make this easier somehow than the same equation without it, but I'm failing to see the simplification that this allows. Anyone know?