4. The curve \(C\) has the equation \(y = x ^ { 2 } - 5 x + 2 \ln \frac { x } { 3 } , x > 0\).
- Show that the normal to \(C\) at the point where \(x = 3\) has the equation
$$3 x + 5 y + 21 = 0$$
- Find the \(x\)-coordinates of the stationary points of \(C\).