Write Each Rational Expression in Lowest Terms, and Give the Domain

Essay

Write each rational expression in lowest terms, and give the domain.
(a) $\frac{33 p^{5}}{11 p^{8}}$
(b) $\frac{9+k}{k^{2}-81}$
(c) $\frac{y^{3}+27}{y^{2}-9}$