# Math Help - some basic set questions

1. ## some basic set questions

(1) Is (B n A) n (A' u C') equivalent to B n [ A n (A' n C')] ??

If so , what law is that ? Distributive laws ?

(2) why is A' n (A' u B) = A' ??

Can someone explain the above 2 questions to me .. Thanks a lot !!

2. Originally Posted by thereddevils
(2) why is A' n (A' u B) = A' ??
You should know $P \subseteq Q\; \Rightarrow \;P \cap Q = P$

Then observe that $A' \subseteq A' \cup B$.

3. Thanks Plato , i got it . How about (1) ?

4. Originally Posted by thereddevils
Let $X=B\cap A$ then $X\cap(A'\cup C')=(X\cap A')\cup (X\cap C')$