9. If the system of equations $x - k y - z = 0 , k x - y - z = 0 , x + y - z = 0$ has a non-zero solution, then possible values of $k$ are : (A) $- 1,2$ (B) 1,2 (C) 0,1 (D) $- 1,1$
9. If the system of equations $x - k y - z = 0 , k x - y - z = 0 , x + y - z = 0$ has a non-zero solution, then possible values of $k$ are :\\
(A) $- 1,2$\\
(B) 1,2\\
(C) 0,1\\
(D) $- 1,1$\\