The segment from (-1,4) to (2,-2) extended three times then terminal point of segment is

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.