\[B = 
\begin{bmatrix} 
 7  \\ 
 7
\end{bmatrix}, \qquad 
\begin{bmatrix} 
 -3  \\ 
 -1
\end{bmatrix}, \qquad \]
\[C = 
\begin{bmatrix} 
 3  \\ 
 1
\end{bmatrix}, \qquad 
\begin{bmatrix} 
 -1  \\ 
 -5
\end{bmatrix}, \qquad .\]

\begin{solution}
Solution:
\[\underset{C \leftarrow B}{P} =
\begin{bmatrix} 
2 & -1   \\ 
-1 & 0
\end{bmatrix}
\]
\end{solution}