(-12, 5) is the point K
To get the x coordinate, you have to see how far you went from J to M in the x-directioon. -3 - 6 = -9 so to go on to K subtract 9 again -3 - 9 = -12 for the x
Do the same for the y-coordinate
4 - 3 = 1 so add 1 again
4 + 1 = 5
Thus the point (-12, 5)