Answer :
Answer:
[tex]x_{1} = \frac{176}{127} + \frac{71}{127}x_{4}\\\\ x_{2} = \frac{284}{127} + \frac{131}{254}x_{4}\\\\x_{3} = \frac{845}{127} + \frac{663}{254}x_{4}\\[/tex]
Step-by-step explanation:
As the given Augmented matrix is
[tex]\left[\begin{array}{ccccc}9&-2&0&-4&:8\\0&7&-1&-1&:9\\8&12&-6&5&:-2\end{array}\right][/tex]
Step 1 :
[tex]r_{1}[/tex]↔[tex]r_{1} - r_{2}[/tex]
[tex]\left[\begin{array}{ccccc}1&-14&6&-9&:10\\0&7&-1&-1&:9\\8&12&-6&5&:-2\end{array}\right][/tex]
Step 2 :
[tex]r_{3}[/tex]↔[tex]r_{3} - 8r_{1}[/tex]
[tex]\left[\begin{array}{ccccc}1&-14&6&-9&:10\\0&7&-1&-1&:9\\0&124&-54&77&:-82\end{array}\right][/tex]
Step 3 :
[tex]r_{2}[/tex]↔[tex]\frac{r_{2}}{7}[/tex]
[tex]\left[\begin{array}{ccccc}1&-14&6&-9&:10\\0&1&-\frac{1}{7} &-\frac{1}{7} &:\frac{9}{7} \\0&124&-54&77&:-82\end{array}\right][/tex]
Step 4 :
[tex]r_{1}[/tex]↔[tex]r_{1} + 14r_{2}[/tex] , [tex]r_{3}[/tex]↔[tex]r_{3} - 124r_{2}[/tex]
[tex]\left[\begin{array}{ccccc}1&0&4&-11&:-8\\0&1&-\frac{1}{7} &-\frac{1}{7} &:\frac{9}{7} \\0&0&- \frac{254}{7} &\frac{663}{7} &:-\frac{1690}{7} \end{array}\right][/tex]
Step 5 :
[tex]r_{3}[/tex]↔[tex]\frac{r_{3}. 7}{254}[/tex]
[tex]\left[\begin{array}{ccccc}1&0&4&-11&:-8\\0&1&-\frac{1}{7} &-\frac{1}{7} &:\frac{9}{7} \\0&0&1&-\frac{663}{254} &:-\frac{1690}{254} \end{array}\right][/tex]
Step 6 :
[tex]r_{1}[/tex]↔[tex]r_{1} - 4r_{3}[/tex] , [tex]r_{2}[/tex]↔[tex]r_{2} + \frac{1}{7} r_{3}[/tex]
[tex]\left[\begin{array}{ccccc}1&0&0&-\frac{71}{127} &:\frac{176}{127} \\0&1&0&-\frac{131}{254} &:\frac{284}{127} \\0&0&1&-\frac{663}{254} &:\frac{845}{127} \end{array}\right][/tex]
∴ we get
[tex]x_{1} = \frac{176}{127} + \frac{71}{127}x_{4}\\\\ x_{2} = \frac{284}{127} + \frac{131}{254}x_{4}\\\\x_{3} = \frac{845}{127} + \frac{663}{254}x_{4}\\[/tex]