There are various ways in which you could do this problem. I'm going to share what I think is one of the faster ways.
Instead of thinking of jumping from (-1,4) TO (2,-2), Consider the horiz. jump separately and the vertical jump separately. From -1 to 2 is 3 units. Three times that is 9 units. Add 9 to -1, obtaining 8. That's the horiz. component of the terminal point.
From 4 to -2 is -6 units. Mult. that by 3. The result is the vert. comp of the terminal point.
