I WILL GIVE BRAINLIST PLEASE HELP

Is the set of rational expressions closed under ​subtraction​? Explain p(x) - r(x) = ______________
q(x) s(x)
2. Is the set of rational expressions closed under ​multiplication​? Explain ( p(x) ) ( r(x) ) = _______________
q(x) s(x)
3. Is the set of rational expressions closed under ​division​? Explain
p(x) ÷ r(x) = ________________ q(x) s(x)