3x+ky=11
2x-4y=-6
-----------------
6x + 2ky = 22
6x - 12y = -18
---------------------
(2k + 12) y = 40 | falls k ≠ -6
y = 40/(2k + 12)
y = 20/(k+6)
2x-4y=-6 ==> 2x - 80/(k+6) = - 6
2x = - 6 + 80/(k+6)
x = -3 + 40/(k+6)
L = { (-3 + 40/(k+6) | 20/(k+6) ) }, falls k ≠ -6
Erst mal nachrechnen!
und dann:
Betrachte den Fall k=-6 noch separat.