Using properties of sets, show that for any two sets A and B, (A∪B)∩(A∩B′)=A.
We need to show (A∪B)∩(A∩B)′=A
Now,
(A∪B)∩(A∩B′) = { (A∪B)∩A} ∩B′
[Using associative property]
= {(A∩A)∪(B∩A) } ∩B′
[∴A∩A=A and B∩A=A∩B, by commutative law]
= A∩B′ [ ∵A∪(A∩B)=A]
= A