\[B = 
\begin{bmatrix} 
 -9  \\ 
 -6
\end{bmatrix}, \qquad 
\begin{bmatrix} 
 -15  \\ 
 -9
\end{bmatrix}, \qquad \]
\[C = 
\begin{bmatrix} 
 3  \\ 
 0
\end{bmatrix}, \qquad 
\begin{bmatrix} 
 3  \\ 
 3
\end{bmatrix}, \qquad .\]

\begin{solution}
Solution:
\[\underset{C \leftarrow B}{P} =
\begin{bmatrix} 
-1 & -2   \\ 
-2 & -3
\end{bmatrix}
\]
\end{solution}