f) IS true here is a proof:

assume AUB = A B.

Assume xεA ====> xεA v xεΒ <====> xε(ΑUB) ====> xε(A B) (Since AUB = A B.) and xε(A B)=====> xεA & xεB ====> xεB.

Hence .... A is a subset of B .In the same way we prove B is a subset of A

e) is also true here is a proof:

(AUB')' U A' = (A' B)UA' = (A' T)U(A' B) =

A' (TUB) = A' T = A'

SINCE :

A' T=A' and BUT=T WHERE T is for true