Chapter 9.1, Problem 19E

In Exercises 19-20, a few steps in the process of simplifying the given matrix to row-echelon form, with Is down the diagonal from tipper left to lower right, and 0s below the Is, are shown. Fill in the missing numbers in the steps that are shown.

$\begin{array}{l}\left[\begin{array}{lll}1\hfill & -1\hfill & 1\hfill \\ 2\hfill & 3\hfill & -1\hfill \\ 3\hfill & -2\hfill & -9\hfill \end{array}|\begin{array}{l}8\\ -2\\ 9\end{array}\right]\to \left[\begin{array}{lll}1\hfill & -1\hfill & 1\hfill \\ 0\hfill & 5\hfill & \boxed{}\hfill \\ 0\hfill & 1\hfill & \boxed{}\hfill \end{array}|\begin{array}{l}8\\ \boxed{}\\ \boxed{}\end{array}\right]\\ \to \left[\begin{array}{lll}1\hfill & -1\hfill & 1\hfill \\ 2\hfill & 3\hfill & \boxed{}\hfill \\ 3\hfill & -2\hfill & \boxed{}\hfill \end{array}|\begin{array}{l}8\\ \boxed{}\\ \boxed{}\end{array}\right]\end{array}$