Practice Test 9

Let $C$ and $D$ be $3\times 2$ matrices:

$$C=\begin{bmatrix}1&-4\0&2\5&-1\end{bmatrix},\quad D=\begin{bmatrix}-2&3\1&0\-5&4\end{bmatrix}.$$

Based on the matrices defined, what is $C-D$?

Let $A$ be a $2 \times 3$ matrix and $B$ be a $3 \times 2$ matrix:

$$A=\begin{bmatrix}2&0&-1\3&1&4\end{bmatrix},\quad B=\begin{bmatrix}1&-2\0&5\-3&1\end{bmatrix}.$$

Given the matrices above, what are the dimensions of the matrix $AB$?