5.2b Change of Base of Logarithms (Example 3 & 4)

Example 3
Given that ${\log }_{p}3=h$   and ${\log }_{p}5=k$  , express the following in term of h and or k.
(a) ${\log }_p\frac{5}{3}$

(b) ${\log }_{15}75$

Example 4
Given that ${\log }_{3}x=b$  , express ${\log }_{x}9x$ in term of b.