Answer:
A U { } = A
Explanation:
Union is one of the operations that are performed on sets. In union, the elements of involved sets are combined and repetitive elements are removed (written only once)
Given
A U { } = ?
Whenever union will be taken of any set and empty set the answer will be the set.
Similarly, when union of set A will be taken with empty set the result will be set A.
Hence,
A U { } = A