1) (4,-2) + (2, 5) = (6,3)
2) (-3,1) + (4,-7) = (1,-6)
3) (0,-4) + (-6,7) = (-6,3)
4) (3,-3) + (3,-3) = (6,-6)
5) (5, 4) + (1,-4) = (6,0)
6) (-5,3) + (5,-3) =(0,0)