1. Consider the following vectors
$b_1 = \begin{pmatrix} 7 \\ 5 \end{pmatrix}$, $b_2 = \begin{pmatrix} -3 \\ -1 \end{pmatrix}$, $c_1 = \begin{pmatrix} 1 \\ -5 \end{pmatrix}$, $c_2 = \begin{pmatrix} -2 \\ 2 \end{pmatrix}$,
and consider the bases $B = \{b_1, b_2\}$, $C = \{c_1, c_2\}$.
(a) Find $C \stackrel{P}{\leftarrow} B$ and $B \stackrel{P}{\leftarrow} C$.
(b) for $x = \begin{pmatrix} 4 \\ 4 \end{pmatrix}$, compute $[x]_B$, $[x]_C$.