i) For what value(s) of k does the system have;

no solutions, a unique solution, infinitely many solutions?

x + 2y - z = -3

0x + y - k-3 = -5

0x + 0y + k^2 -2k = 5k + 11

ii) each of these equations represents a plane. In each case in i) give a geometric description of the intersection of the three planes.

I have answered this already, but have gotten myself hopelessly confused, and the more I spend time on it, the worse I get. PLEASE HELP. I just can't seem to work out how to find the values of k.