#### Answer

Part A:
Since A and B are not the same dimensions, A + B is undefined.
Part B:
Since A and B are not the same dimensions, A - B is undefined.
Part C:
$\begin{bmatrix}
9\\
6\\
-3\\
\end{bmatrix}$
Part D:
Since A and B are not the same dimensions, 3A - 2B is undefined.

#### Work Step by Step

The dimensions of A are (3 x 1).
The dimensions of B are (1 x 3).
Part A:
Since A and B are not the same dimensions, A + B is undefined.
Part B:
Since A and B are not the same dimensions, A - B is undefined.
Part C:
$\begin{bmatrix}
3(3)\\
3(2)\\
3(-1)\\
\end{bmatrix}$ = $\begin{bmatrix}
9\\
6\\
-3\\
\end{bmatrix}$
Part D:
Since A and B are not the same dimensions, 3A - 2B is undefined.