<exercise checkit-seed="0012" checkit-slug="E1" checkit-title="Linear systems, vector equations, and augmented matrices">
<statement>
<p> Consider the system of equations</p>
<me>\begin{matrix}
x & + & 2 \, y & + & z & = & 5 \\
-2 \, x & - & 3 \, y & - & z & = & -5 \\
x & + & y & + & z & = & 4 \\
2 \, x & + & 4 \, y & & & = & 2 \\
\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}{ccc|c}
1 & 2 & 1 & 5 \\
-2 & -3 & -1 & -5 \\
1 & 1 & 1 & 4 \\
2 & 4 & 0 & 2
\end{array}\right] </me>
</li>
<li>
<me> x_{1} \left[\begin{array}{c}
1 \\
-2 \\
1 \\
2
\end{array}\right] + x_{2} \left[\begin{array}{c}
2 \\
-3 \\
1 \\
4
\end{array}\right] + x_{3} \left[\begin{array}{c}
1 \\
-1 \\
1 \\
0
\end{array}\right] = \left[\begin{array}{c}
5 \\
-5 \\
4 \\
2
\end{array}\right] </me>
</li>
</ol>
</answer>
</exercise>