okay, this is pretty simple ! so basically, you are going to reflect the point (p) over the red line that was so nicely placed. since you are are going to imagine the red line is 0,0 (where you would start if you are going to fine the coordinates of a plot point). since the plot point is only one coordinate away from the red line, you would only need to move over one coordinate to the right. If i'm correct, the answer should be -1,4.
