8. Find the vertex of 'C'

The $\triangle ABC$ has the following vertices $A($−9, 15$)$, $B($6, 0$)$ and $C(x_3$, $y_3)$. If $G($6, 4$)$ is the centroid, find the values of $x_3$ and $y_3$.

 

$x_3 =$

 

$y_3 =$