Let B = \{b_1, b_2\} and C = \{c_1, c_2\} be bases for $\mathbb{R}^2$. Find the change-of-coordinates matrix from B to C and the change-of-coordinates matrix from C to B.
$\begin{bmatrix} -5\\2 \end{bmatrix}$, $b_2 = \begin{bmatrix} 3\\-1 \end{bmatrix}$, $c_1 = \begin{bmatrix} 1\\2 \end{bmatrix}$, $c_2 = \begin{bmatrix} 1\\1 \end{bmatrix}$
Find the change-of-coordinates matrix from B to C
$P_{C \leftarrow B} = \begin{bmatrix} \Box & \Box\\\Box & \Box \end{bmatrix}$ (Simplify your answers.)
