<exercise checkit-seed="0005" checkit-slug="E1" checkit-title="Linear systems, vector equations, and augmented matrices">
<statement>
<p> Consider the system of equations</p>
<me>\begin{matrix}
-2 \, x_{1} & + & 6 \, x_{2} & - & 6 \, x_{3} & - & 2 \, x_{4} & = & 4 \\
3 \, x_{1} & - & 9 \, x_{2} & + & 9 \, x_{3} & + & x_{4} & = & 0 \\
-3 \, x_{1} & + & 9 \, x_{2} & - & 9 \, x_{3} & - & 2 \, x_{4} & = & 3 \\
\end{matrix}</me>
<ol>
<li> Write an augmented matrix corresponding to this system. </li>
<li> Write a vector equation corresponding to this system. </li>
</ol>
</statement>
<answer>
<ol>
<li><me>\left[\begin{array}{cccc|c}
-2 & 6 & -6 & -2 & 4 \\
3 & -9 & 9 & 1 & 0 \\
-3 & 9 & -9 & -2 & 3
\end{array}\right]</me></li>
<li><me>x_{1} \left[\begin{array}{c}
-2 \\
3 \\
-3
\end{array}\right] + x_{2} \left[\begin{array}{c}
6 \\
-9 \\
9
\end{array}\right] + x_{3} \left[\begin{array}{c}
-6 \\
9 \\
-9
\end{array}\right] + x_{4} \left[\begin{array}{c}
-2 \\
1 \\
-2
\end{array}\right] = \left[\begin{array}{c}
4 \\
0 \\
3
\end{array}\right]</me></li>
</ol>
</answer>
</exercise>