Answer:
{2, 3, 5, 6, 8, 9}
Explanation:
The universal set is
U = {2, 3, 4, 5, 6, 7, 8, 9}
M = {3, 4, 7, 9}
N = {4, 6, 7}
M n N = {4, 7}
The bar above M n N means the complement of M n N which is all elements of the universal set that are not in M n N.
Answer: {2, 3, 5, 6, 8, 9}