# algebraic laws of sets

#### may

Hello mayThis uses the Distributive Law:
$$\displaystyle (P \cup Q)\cap (P \cup R) = P \cup (Q \cap R)$$
where I have replaced $$\displaystyle P$$ by $$\displaystyle B'$$, $$\displaystyle Q$$ by $$\displaystyle \oslash$$ and $$\displaystyle R$$ by $$\displaystyle A'$$.

Yes, I'm rather afraid that you do. As I said - you'll need lots of practice!

$$\displaystyle \oslash \cap A' = \oslash$$ uses what I have always known as an Identity Law, but others sometimes refer to as a Domination Law.

See, for example, here.
Oh,thanks Grandad at last i start to figure out how to do this type of question.thank you very much(Wink)

erm i want to ask another question..same topic do i need to put the question in new thread or at here?