Answer
$$\begin{pmatrix}-\frac{3}{10}&-\frac{1}{5}&\frac{3}{10}\\ \frac{9}{10}&\frac{3}{5}&\frac{1}{10}\\ -\frac{1}{5}&\frac{1}{5}&\frac{1}{5}\end{pmatrix}$$
Work Step by Step
To use a graphing calculator to find the inverse of a Matrix, first select (2nd) and ($x^{-1})$ to bring up the Matrix menu. Next, scroll to edit, select Matrix [A], and plug in the given Matrix. (You may have to change the dimensions of the Matrix.) Finally, going back to the main screen, select (2nd) and ($x^{-1})$. Then, choose Matrix A, and press the $x^{-1}$ to find its inverse. Doing this, we find:
$$\begin{pmatrix}-\frac{3}{10}&-\frac{1}{5}&\frac{3}{10}\\ \frac{9}{10}&\frac{3}{5}&\frac{1}{10}\\ -\frac{1}{5}&\frac{1}{5}&\frac{1}{5}\end{pmatrix}$$