E-STAR - Student

Which of the following statements is true?

If x ∈ A and x ∉ B, then x ∉ (A ∪ B)

If x ∉ A and x ∉ B, then x ∉ (A ∪ B)

If A ⊆ B, then A ∪ B = A

If A ∩ B = Ø, then A \ B = Ø