<exercise checkit-seed="0004" checkit-slug="E1" checkit-title="Linear systems, vector equations, and augmented matrices">
<statement>
<p> Consider the augmented matrix </p>
<me>\left[\begin{array}{ccc|c}
1 & 0 & 2 & 3 \\
-2 & 1 & -5 & -2 \\
-3 & 1 & -7 & -4 \\
-2 & 1 & -5 & -5
\end{array}\right]</me>
<ol>
<li> Write a system of scalar equations corresponding to this augmented matrix. </li>
<li> Write a vector equation corresponding to this augmented matrix. </li>
</ol>
</statement>
<answer>
<ol>
<li><me>\begin{matrix}
x & & & + & 2 \, z & = & 3 \\
-2 \, x & + & y & - & 5 \, z & = & -2 \\
-3 \, x & + & y & - & 7 \, z & = & -4 \\
-2 \, x & + & y & - & 5 \, z & = & -5 \\
\end{matrix}</me></li>
<li><me>x_{1} \left[\begin{array}{c}
1 \\
-2 \\
-3 \\
-2
\end{array}\right] + x_{2} \left[\begin{array}{c}
0 \\
1 \\
1 \\
1
\end{array}\right] + x_{3} \left[\begin{array}{c}
2 \\
-5 \\
-7 \\
-5
\end{array}\right] = \left[\begin{array}{c}
3 \\
-2 \\
-4 \\
-5
\end{array}\right]</me></li>
</ol>
</answer>
</exercise>