Answer:
An augmented matrix refers to a matrix formed by appending the columns of two matrices.
The perfect example to show this is a linear systems of equations, because there we have a matrix formed by the coeffcients of the variables only, and we have a second matrix formed by the constant terms of the system.
If we have the system

The two maxtrix involved here are
![\left[\begin{array}{ccc}2&3\\1&-4\end{array}\right] \\\left[\begin{array}{ccc}5\\9\end{array}\right]](https://img.qammunity.org/2020/formulas/mathematics/middle-school/ucmp22p06j5d8so25139gc8x3t32s3hulm.png)
However, to solve the system using matrices, we have to formed an augmented matrix
![\left[\begin{array}{ccc}2&3&5\\1&-4&9\end{array}\right]](https://img.qammunity.org/2020/formulas/mathematics/middle-school/bonk3deh8mga0x2vkc7hrpt4mdyj4grw70.png)
So, as we defined it at the beginning, an augmented matrix is the appending of colums from two matrices to form one.