ANSWER :
a. {2, 6, 9}
b. {6}
EXPLANATION :
From the problem, we have the sets :
A' denotes the elements that are NOT present in A but present in U.
B' denotes the elements that are NOT present in B but present in U.
That will be :
a. A' ∪ B'
The symbol ∪ denotes the union of two sets.
That will be :
b. A' ∩ B
The symbol ∩ denotes the intersection or common elements of the two sets
That will be :