Solve the equation \(3 \log _ { a } x = \log _ { a } 8\).
Show that
$$3 \log _ { a } 6 - \log _ { a } 8 = \log _ { a } 27$$
The point \(P ( 3 , p )\) lies on the curve \(y = 3 \log _ { 10 } x - \log _ { 10 } 8\).
Show that \(p = \log _ { 10 } \left( \frac { 27 } { 8 } \right)\).
The point \(Q ( 6 , q )\) also lies on the curve \(y = 3 \log _ { 10 } x - \log _ { 10 } 8\).
Show that the gradient of the line \(P Q\) is \(\log _ { 10 } 2\).