Are these a rational function?

1.) y = 3/x
2.) q(x) = (5x-30) / (10x +20)
3.)(2x-5)/ x-x
4.)p(x) = 5x / (x^3 -27)
5.)y = √(2x) / x+1
6.) y = 3/(5-x^2)
7.) f(x) = (x+5)/x
8.) g(x) = x^0 / (x

Please reply asap