Using Venn diagram, prove the following: a) (A + B)' = A' B' b) (A B)'= A' + B' c) x (y+z) = x y + x z Prove the following using Boolean algebra: a) (A + C)(A B + A B') + AC + C = A + C b) A' (A + B) + (B + A A)(A + B') = A + A' B