I really don’t know I’m just tryna get points but sorry
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:
the answer is
C
if i am wrong let me know
Step-by-step explanation:
David's score on his fifth test would be an 87. If you add up all the scores from his first to his fourth test, it would 363. However, since there are five tests, in order to get a 90 percent, the sum of all five test scores would be 450. 450 - 363 = 87.