Answer:
4 and 9
Explanation:
I am going to use an upper case E for the symbol in the answers. The E symbol means "is a member of set..."
So " 1 E A " means "1 is a member of set A."
And " 4 E A" means "4 is a member of set A.
Now at the beginning of the question they told you what numbers were in which sets. 1 through 9 are in set U. But only 4 and 9 are in set A. The contents of the set are listed in between a pair of grouping symbols { } that are kind of squiggly brackets. That's how you know what is in the set.
Since set A only contains 4 and 9, those are your two correct answers:
"4 E A" AND "9 E A"