Chapter 10 - 10.2 - Operations with Matrices - 10.2 Exercises - Page 724: 12

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.

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.