Respuesta :
Answer:
The set of integers is closed under addition, subtraction, and multiplication because when I add, subtract, or multiply any integers, the result is always an integer. The set is not closed under division because 2 + 4 = 0.5, and 0.5 is not an integer.
Answer:
a/b + c/d = (ad+bc)/bd, so closed under addition.
a/b - c/d = (ad-bc)/bd, so closed under subtraction.
a/b * c/d = (ac)/(bd), so closed under multiplication.
a/b / c/d = (ad)/(bc), so closed under division.
Step-by-step explanation: