(a) Given that A=\left(\begin{array}{cc}

6 & -2 \\

-4 & 1

\end{array}\right) \text { Show that } \mathbf{A}^{\mathbf{2}}=\mathbf{7 A}+2 \mathbf{I} The matrix M is given by \mathbf{M}=\left(\begin{array}{ccc}

2 & 1 & -3 \\

-1 & 1 & 3 \\

2 & -1 & -1

\end{array}\right) find M-1