Need help with relation properties using logical operators

Question

I was wondering how should I proceed to determine what will be in the relation and what will not given these properties. Operating with integers:

$R: \{(a, b)|(a= 0∧b= 0)∨ GCD(a, b) = 5\}$

Answer 1

R = { (a, b) : (a = 0 ∧ b = 0) ∨ exists coprime j,k with (a = 5j ∧ b = 5k) }

{ x : P(x) or Q(x) } = { x : P(x) } $\cup$ { x : Q(x) }