Thank you very much for your help!
I'm still a bit confused on part (b) - I can see that α^4=α+1 and how this helps to write elements as α^n.
I'm not sure how I could write elements such as α^2 + 1 and α^2+α+1 as α^n?? Also with other elements α^3+α, α^3+1, α^3+α^2+α, α^3+α+1 and α^3+α^2+α+1...