Chapter 6 - Summary, Review, and Test - Review Exercises - Page 656: 21

$\begin{bmatrix}-1&-16\\8&1\end{bmatrix}$

We are given the matrices: $A=\begin{bmatrix}2&-1&2\\5&3&-1\end{bmatrix}$ $B=\begin{bmatrix}0&-2\\3&2\\1&-5\end{bmatrix}$ Compute $AB$: $AB=\begin{bmatrix}2&-1&2\\5&3&-1\end{bmatrix}\begin{bmatrix}0&-2\\3&2\\1&-5\end{bmatrix}$ $=\begin{bmatrix}0-3+2&-4-2-10\\0+9-1&-10+6+5\end{bmatrix}$ $=\begin{bmatrix}-1&-16\\8&1\end{bmatrix}$