<exercise checkit-seed="0010" checkit-slug="E1" checkit-title="Linear systems, vector equations, and augmented matrices">
<statement>
<p>Consider the vector equation.</p>
<me> x_{1} \left[\begin{array}{c}
1 \\
0 \\
1 \\
0
\end{array}\right] + x_{2} \left[\begin{array}{c}
6 \\
1 \\
-1 \\
2
\end{array}\right] + x_{3} \left[\begin{array}{c}
5 \\
2 \\
-4 \\
2
\end{array}\right] = \left[\begin{array}{c}
-7 \\
-1 \\
0 \\
-2
\end{array}\right] </me>
<ol>
<li> Write a system of scalar equations corresponding to this vector equation. </li>
<li> Write an augmented matrix corresponding to this vector equation. </li>
</ol>
</statement>
<answer>
<ol>
<li>
<me>\begin{matrix}
x & + & 6 \, y & + & 5 \, z & = & -7 \\
& & y & + & 2 \, z & = & -1 \\
x & - & y & - & 4 \, z & = & 0 \\
& & 2 \, y & + & 2 \, z & = & -2 \\
\end{matrix}</me>
</li>
<li>
<me> \left[\begin{array}{ccc|c}
1 & 6 & 5 & -7 \\
0 & 1 & 2 & -1 \\
1 & -1 & -4 & 0 \\
0 & 2 & 2 & -2
\end{array}\right] </me>
</li>
</ol>
</answer>
</exercise>