Algebra and Trigonometry 10th Edition

Published by Cengage Learning
ISBN 10: 9781337271172
ISBN 13: 978-1-33727-117-2

Chapter 10 - 10.2 - Operations with Matrices - 10.2 Exercises - Page 725: 51

Answer

Part A: $\begin{bmatrix} 7 & 7 & 14\\ 8 & 8 & 16\\ -1 & -1 & -2\\ \end{bmatrix}$ Part B: $\begin{bmatrix} 13\\ \end{bmatrix}$ Part C: Not possible.

Work Step by Step

A has 3 rows and 1 column (3 x 1). B has 1 row and 3 columns (1 x 3). Part A: $\begin{bmatrix} 7(1) & 7(1) & 7(2)\\ 8(1) & 8(1) & 8(2)\\ (-1)(1) & (-1)(1) & (-1)(2)\\ \end{bmatrix}$ = $\begin{bmatrix} 7 & 7 & 14\\ 8 & 8 & 16\\ -1 & -1 & -2\\ \end{bmatrix}$ Part B: $\begin{bmatrix} 1(7) + 1(8) + 2(-1)\\ \end{bmatrix}$ = $\begin{bmatrix} 7 + 8 - 2\\ \end{bmatrix}$ = $\begin{bmatrix} 13\\ \end{bmatrix}$ Part C: Since the number of columns in A does not equal the number of rows in A, AA is not possible.
Update this answer!

You can help us out by revising, improving and updating this answer.

Update this answer

After you claim an answer you’ll have 24 hours to send in a draft. An editor will review the submission and either publish your submission or provide feedback.