If x∈Z, y∈Z, x > 0 and y < 0 then 1y > 1x.
If x3+y3+z3 = 3xyz, then which one of the following is true ?
(1) x+y+z =1
(2) x-y+z = 0
(3) either x+y+z = 0 or x=y=z
(4) neither x+y+z = 0 or x=y=z