The function rref(A) returns the row echelon (Gauss-Jordan) form of the matrix A.

$\mathrm{with}\left(\mathrm{MTM}\right)\:$

$A≔\mathrm{Matrix}\left(\left[\left[1\,2\,1\right]\,\left[2\,4\,2\right]\,\left[2\,8\,1\right]\right]\right)$

$A≔\left[\begin{array}{ccc}1& 2& 1\\ 2& 4& 2\\ 2& 8& 1\end{array}\right]$

$\mathrm{rref}\left(A\right)$

$\left[\begin{array}{ccc}1& 0& \frac{3}{2}\\ 0& 1& -\frac{1}{4}\\ 0& 0& 0\end{array}\right]$