"3 units down" affects only the y coordinate (making it 3 units lower, or -3), while "4 units to the left" affects the x coordinate (-4). To solve this, we just need to do (x-4, y-3) with each of the points of the shape!
therefore:
(2, -1) (1, -4) (3, -5) and (5, -3) become (-2, -4), (-3, -7), (-1, -8), and (1, -6). These will be the 4 new points of the quadrilateral :) Let me know if I can help with explaining any more!
