Answer
The matrix is in row-echelon form. But it is not in the reduced echelon form.
Work Step by Step
The matrix is
$$
\left[\begin{array}{cccc}{1} & {0} & {1} & {1} \\ {0} & {1} & {2} & {1} \\ {0} & {0} & {0} & {1}\end{array}\right]
$$
in row-echelon form. But it is not in the reduced echelon form.
