Solve Q(√7,√5) and Prove φ(4√3) = ± 4√3 | Galois Theory Help

[LARaiders20]

I am so confused with these two questions. Can anyone help me out?

1) Please find [Q((√7 , √5) : Q] by finding f(x) such that Q (√7 , √5) ≅ Q[x]/(f(x)),

2) Prove that φ(4root√3) = ± 4root√3, Given that φ ∈ Gal(Q(4root√3)|Q)

 

[Simon Bridge]

Welcome to PF;
What is your understanding of what these questions are asking?
How have you tried to solve them so far?
Where does your confusion lie?