Decide whether the followdng pairs of sets are always equal. If not equal, give a countere...

Decide whether the followdng pairs of sets are always equal. If not equal, give a counterexample.

a. A – B and B – A

b. A – B and A ∩

c. B –A andB ∪ A if B ⊆ A

d. B ∪ ∅ and B ∩ B