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.
