Answer
See solution
Work Step by Step
The change of coordinate matrix from B to the standard basis is $\begin{bmatrix}
4&6\\5&7
\end{bmatrix}$, so the change of coordinate matrix from the standard basis to B is its inverse: $\begin{bmatrix}
-3.5&3\\2.5&-2
\end{bmatrix}$.
The B coordinate vector [x]$_B$ is $\begin{bmatrix}
-7\\5
\end{bmatrix}$
