Looking for the solution for the picture below

(A - B)' = {1, 2, 3, 5, 6, 7, 8, 9, 10,12, 13}

Explanation:

The roster form of a set is the elements listed inside brackets { }.

In this case it is easy to visualize A - B directly of the Venn diagram: when you subtract from A those elements that are also in B, the result is A - B = {4, 11, 14}.

Now take into account tha (A - B)' is the complement of (A - B), this is all the elements that are not in A - B.

Being A - B = {4, 11, 14} then to show (A - B)' you just have to list all the elements that are on the figure except 4, 11 and 14.

The result, in roster form, is (A - B)' = {1, 2, 3, 5, 6, 7, 8, 9, 10, 12, 13}

The correct answer is -20y