6. Find the g-inverse of the 3 x 3 matrix A where

$$

A =

\begin{bmatrix}

3 & 2 & 1 \\

1 & 1 & 1 \\

3 & 1 & -1

\end{bmatrix}

$$

using the methods presented in each of the Theorems 6.5.1, 6.5.2, 6.5.5, and 6.5.8.