y - 2·s = -1 --> y = 2·s - 1
x = [1, 2, 6] + y·[-5, 1, 3] + s·[2, -1, -2]
hier y einsetzen
x = [1, 2, 6] + (2·s - 1)·[-5, 1, 3] + s·[2, -1, -2]
x = [1, 2, 6] + 2·s·[-5, 1, 3] - 1·[-5, 1, 3] + s·[2, -1, -2]
x = [6, 1, 3] + s·[- 8, 1, 4]
So verstanden ?