Solve a System of Equations in Three Variables Using Augmented Matrices Practice Test

$\left(\begin{array}{ccc|c} 3 & -1 & -7 & -2\\ 12 & -1 & 2 & 5 \end{array}\right)$

$\left(\begin{array}{ccc|c} 3 & -1 & -7 & 2\\ 12 & -1 & 2 & -5\\ 5 & 3 & -1 & -3 \end{array}\right)$

$\left(\begin{array}{ccc|c} 3 & 2 & -7 & 1\\ 12 & -5 & 2 & 1 \\ 5 & 3 & -1 & 3 \end{array}\right)$

$\left(\begin{array}{ccc|c} 3 & -1 & -7 & -2\\ 12 & -1 & 2 & 5\\ 5 & 3 & -1 & 3 \end{array}\right)$

$\left(\begin{array}{ccc|c} 3 & -7 & 2 & 1\\ 12 & 2 & -5 & 1\\ 5 & -1 & -3 & 3 \end{array}\right)$