20 possibilities based on this as a combination not a permutation, 6 nCr 3 = 20
Problem 11) Start with set U = {1,2,3,4,5} and cross off 1,2,3 to be left with A' = {4,5}. We basically erase everything found in set A. You have the correct answer. Nice job.
Problem 12) Start with U = {1,2,3,4,5} and erase '5' to be left with {1,2,3,4}. So B' = {1,2,3,4}. You are correct here as well.
I can't help with the other problems since either letters, numbers or symbols are missing. Please make a new post and provide those updates.
In this case, we must use trigonometry to find the value of x:

Thus the value of x rounded to the nearest tenth is <u>8.2</u>
<u></u>
Hope that helps!
Answer:
i think n = 4
Step-by-step explanation:
3(n+7) = 33
3n+21 = 33
3n = 12
n = 4
457 divided by 4 118.75 i do not have the long division but you basically just put 4 into 457 and stuff so you do 4 into 45 which is 11.25 then 4 into 7
Which is 1.75 then put that together getting 118.75