kx + y + z = 1
x + ky + z = 1
x + y + kz = 1
in unknowns x, y, and z and where k is a real number.
(a) For what value(s) of k does the system have infinitely many solutions ?
(b) For what value(s) of k is the system inconsistent?
(c) For what value(s) of k does the system have exactly one solution?