I am to find the eigenvalues and corresponding eigenvectors of the following matrix:

[3 -1 -1]

[-12 0 5]

[4 -2 -1]

Here is what I have so far:

det(I - A) = det [-3 1 1], [12 -5], [-4 2 +1] = (-3)()(+1)

I know that this is not completely correct, but not sure how to finish. Thanks in advance.