Answer:
Explanation:
The set of imaginary numbers is CLOSED to addition and subtraction, but not multiplication and division. A set is closed to an operation if that operation can be performed on any numbers in that set and the answer will still be in the set. a is called the real part, and b is called the imaginary part.
The set of integers is closed for addition, subtraction, and multiplication but not for division. Calling the set 'closed' means that you can execute that operation with any of the integers and the resulting answer will still be an integer.