This is impossible to answer without knowing what the sets A and B contain (and what ξ even refers to - universal set?).
However, we have
(A U B)' = A' ∩ B'
so that
(A ∩ B) U (A U B)' = (A ∩ B) U (A' ∩ B') = (A U A') ∩ (B U B')
If ξ is indeed the universal set, then both A U A' = ξ and B U B' = ξ, so we end up with ξ ∩ ξ = ξ.
Answer:
yes
Step-by-step explanation:
Answer: <span>Postulate 4: If two points lie in a plane, the line containing them lies in that plane.
</span>That is because two points, call them A and B, always form a line, and so, given that they form the line AB and they are in the plane Q, the line AB is in the plane Q.<span />