College Algebra (6th Edition)

Published by Pearson
ISBN 10: 0-32178-228-3
ISBN 13: 978-0-32178-228-1

Chapter 6 - Matrices and Determinants - Exercise Set 6.2 - Page 609: 15

Answer

Solution set: $\{ ( \displaystyle \frac{1}{3}t+1$ , $\displaystyle \frac{1}{3}t$ , $t )$ , $t\in \mathbb{R}\}$

Work Step by Step

Augmented matrix: $\left[\begin{array}{lllll} 2 & 1 & -1 & | & 2\\ 3 & 3 & -2 & | & 3 \end{array}\right]\left\{\begin{array}{l} \leftarrow-R_{1}+R_{3}\\ . \end{array}\right.$ $\left[\begin{array}{lllll} 1 & 2 & -1 & | & 1\\ 3 & 3 & -2 & | & 3 \end{array}\right]\left\{\begin{array}{l} .\\ \leftarrow-3R_{1}+R_{3}. \end{array}\right.$ $\left[\begin{array}{lllll} 1 & 2 & -1 & | & 1\\ 0 & -3 & 1 & | & 0 \end{array}\right]\left\{\begin{array}{l} .\\ \div(-3). \end{array}\right.$ $\left[\begin{array}{lllll} 1 & 2 & -1 & | & 1\\ 0 & 1 & -1/3 & | & 0 \end{array}\right]$ The system is consistent and does not have a unique solution. Let $z=t, t\in \mathbb{R}$. Substituting into row 2, $y-\displaystyle \frac{1}{3}t=0$ $y=\displaystyle \frac{1}{3}t$ Substituting into row 1, $x+2(\displaystyle \frac{1}{3}t)-t=1$ $x-\displaystyle \frac{1}{3}t=1$ $x=\displaystyle \frac{1}{3}t+1$ Solution set: $\{ ( \displaystyle \frac{1}{3}t+1$ , $\displaystyle \frac{1}{3}t$ , $t )$ , $t\in \mathbb{R}\}$
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.