/sci/ - Science & Math

I keep getting this problem wrong. Can someone help me find find P? It does not accept answers from any calculator I've tried.

The eigenvalues are correct, and are 0,0 and -3. So the row reduced forms of that matrices after substracting the eigenvalues along the diagnol are the identity matrix for -3, and for 0 it is:
[math]\begin{bmatrix} -1 & -3 & 11 \\ 0 & 0 & 0\\0 & 0 & 0\end{bmatrix}[/math]

I'm not really clear on how to solve for P from here. I know it has to do with setting the rref matrices above to Ax = 0, and solving for x, but I tried that and my answer was still wrong.