Elementary Linear Algebra 7th Edition

Published by Cengage Learning
ISBN 10: 1-13311-087-8
ISBN 13: 978-1-13311-087-3

Chapter 2 - Matrices - 2.1 Operations with Matrices - 2.1 Exercises: 4

Answer

$x=-4$ $y=9$

Work Step by Step

$\begin{pmatrix} x+2 & 8 & -3\\ 1 & 2y & 2x \\ 7 & -2 & y+2 \end{pmatrix}=\begin{pmatrix} 2x+6 & 8 & -3\\ 1 & 18 & -8 \\ 7 & -2 & 11 \end{pmatrix}$ All we need to do here is compare elements: $x+2=2x+6$ $2y=18$ $2x=-8$ $y+2=11$ The first and third equations yield the same result: $x+2=2x+6$ $\quad \quad \quad \quad \quad 2x=-8$ $\implies x=2-6=-4$ $\quad \quad x=\frac{-8}{2}=-4$ The second and fourth equations also yield the same result $2y=18$ $\quad \quad \quad \quad \quad y=11-2=9$ $y=\frac{18}{2}=9$
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.