Intermediate Algebra for College Students (7th Edition)

Published by Pearson
ISBN 10: 0-13417-894-7
ISBN 13: 978-0-13417-894-3

Chapter 3 - Section 3.4 - Matrix Solutions to Linear Systems - Exercise Set - Page 229: 33

Answer

No solution or $\varnothing$.

Work Step by Step

The given system of equations is $x-y+3z=4$ $2x-2y+6z=7$ $3x-y+5z=14$ The augmented matrix is $\Rightarrow \left[\begin{array}{ccc|c} 1 & -1 & 3& 4\\ 2 & -2 & 6& 7 \\ 3&-1&5&14 \end{array}\right]$ Perform $R_2\rightarrow R_2-2R_1$ and $R_3\rightarrow R_3-3 R_1$. $\Rightarrow \left[\begin{array}{ccc|c} 1 & -1 & 3& 4\\ 2-2(1) & -2-2(-1) & 6-2(3)& 7-2(4) \\ 3-3(1)&-1-3(-1)&5-3(3)&14-3(4) \end{array}\right]$ Simplify. $\Rightarrow \left[\begin{array}{ccc|c} 1 & -1 & 3& 4\\ 0 & 0 & 0& -1 \\ 0&2&-4&2 \end{array}\right]$ Use back substitution for the second row. $x(0)+y(0)+z(0)=-1$ There are no values of $x,y$ and $z$ for which the above equation satisfy. Hence, the system is inconsistent and has no solution.
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