Precalculus (10th Edition)

Published by Pearson
ISBN 10: 0-32197-907-9
ISBN 13: 978-0-32197-907-0

Chapter 11 - Systems of Equations and Inequalities - Chapter Review - Chapter Test - Page 796: 16

Answer

Inconsistent

Work Step by Step

We are given the system of equations: $\begin{cases} 2x+2y-3z=5\\ x-y+2z=8\\ 3x+5y-8z=-2 \end{cases}$ The augmented matrix associated with the system is: $A=\begin{bmatrix}2&2&-3&|&5\\1&-1&2&|&8\\3&5&-8&|&-2\end{bmatrix}$ Multiply $R_2$ by -1 and add it to $R_1$: $\begin{bmatrix}1&3&-5&|&-3\\1&-1&2&|&8\\3&5&-8&|&-2\end{bmatrix}$ Multiply $R_1$ by -1 and add it to $R_2$: $\begin{bmatrix}1&3&-5&|&-3\\0&-4&7&|&11\\3&5&-8&|&-2\end{bmatrix}$ Multiply $R_1$ by -3 and add it to $R_3$: $\begin{bmatrix}1&3&-5&|&-3\\0&-4&7&|&11\\0&-4&7&|&7\end{bmatrix}$ Multiply $R_2$ by -1 and add it to $R_3$: $\begin{bmatrix}1&3&-5&|&-3\\0&-4&7&|&11\\0&0&0&|&-4\end{bmatrix}$ Multiply $R_2$ by $-\dfrac{1}{4}$: $\begin{bmatrix}1&3&-5&|&-3\\0&1&-\dfrac{7}{4}&|&-\dfrac{11}{4}\\0&0&0&|&-4\end{bmatrix}$ As the last line contains only zeros to the left of the bar and a non zero element to the right, the system is inconsistent.
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