$\displaystyle \log_a(3)=q$ & $\displaystyle \log_a(2)=p$ Express $log_a 72$ in terms of p & q $\displaystyle \log_a(3)=q$ & $\displaystyle \log_a(2)=p$ Express $log_a 72$ in terms of p & q
Currently I have tried nothing as I cannot even figure out where to begin a demonstration kindly will help much 
Many thanks :)

$ \log_a72 = \log_a(2^3 \cdot 3^2)\\
=\log_a (2^3) + \log_a (3^2)\\
= 3 \log_a2 + 2\log_a3\\
= 3p + 2q$
