(4) Find the characteristic polynomials and eigenvalues of the matrices: \left(\begin{array}{cc} 3 & -2 \\ 1 & -1 \end{array}\right) \quad \text { and } \quad\left(\begin{array}{ccc} -1 & 0 & 1

\\ -3 & 4 & 1 \\ 0 & 0 & 2 \end{array}\right)