The calculator function that puts the augmented matrix
[tex] \left[\begin{array}{cc|c}2&4&8\\6&3&-3\end{array}\right] [/tex]
into reduced row-echelon form will give you an identity matrix in the left columns and the solution in the rightmost column:
[tex] \left[\begin{array}{ccc}1&0&-2\\0&1&3\end{array}\right] [/tex]
This corresponds to the first selection.
