[11, -7, 3] - [2, 5, 2] = [9, -12, 1]
a)
[2, 5, 2] + 4 * [9, -12, 1] = [38, -43, 6]
b)
[2, 5, 2] - 1/2 * [9, -12, 1] = [-2.5, 11, 1.5] (nach Kommentar verbessert)
c)
[2, 5, 2] + r * [9, -12, 1] = [80, -92, 10] --> keine Lösung
[2, 5, 2] + r * [9, -12, 1] = [102, -115, 18] --> keine Lösung
Das Boot muss die Richtung geändert haben.