Explanation:
[-3, 10] + r·([-1, 6] - [-3, 10]) = [-1, 6]
[-3, 10] + r·[9, -18] = [-1, 6]
-3 + 9·r = -1 --> r = 2/9
So you can cut the hole line segment in 9 parts with the same length.
So the Point [-1, 6] divided the line in 2 segments on the one side and 7 segments on the other side.
So the ratio is 2:7