Writing Gauss-Jordan Transformation Matrix

Question

I am having trouble writing procedure for Gauss-Jordan transformation matrix in LaTeX.

I want to write something like

      r2 - r1         r3-2r1
[A|I] -------> [A'|I'] ----->

and so on with the corresponding transformations (e.g., r2-r1) on top of the arrows. Could you give me an example code of how to do this? I only know that I need \bmatrix for matrices with [], but I do not know how to split them in between with a vertical line |.

Thanks a lot!

Answer 1

With amsmath you can use

\xrightarrow{r_{2}-r_{1}}

that will produce an arrow wide enough to accommodate the thing on top.

In order to split matrices you need to use array

\left[\begin{array}{@{}cc|c@{}}
   <entries>
\end{array}\right]

With the @{} at both sides you'll get output similar to that of bmatrix.