## Linear Algebra: A Modern Introduction

$\left[\begin{array}{cc|c} 1 & -1 & 0 \\ 2 & 1 &3\end{array}\right]$
The augmented matrix for a system of two linear equations, $m$ and $n$, can be written as: $a_{11}x_1+.....+a_{1n}x_n=b_1 \\ \vdots \\a_{m1}x_1+.....+a_{mn}x_n=b_m$ which is equivalent to: $\left[\begin{array}{ccc|c} a_{11} & \cdots & a_{1n} &b_1\\a_{21} & \cdots & a_{2n} &b_2\\ \vdots & \vdots & \vdots & \vdots \\a_{m1} &\cdots &a_{mn} & b_m \end{array}\right]$ Now, plug the corresponding terms in the above form of the augmented matrix. $\left[\begin{array}{cc|c} 1 & -1 & 0 \\ 2 & 1 &3\end{array}\right]$