Ive got a little problem with this. How do i factor a polynomial over a ternary field? I know how to do it in binary...

in binary: x^7 - 1 = x^7 - 1 = (x+1)(x^3 + x + 1)(x^3 + x^2 + 1)

i get that

and now the question is how do i do it for ternary field

x^5 - 1 = ???

thx a lot for help