I think it’s -1,6 because if it’s 2 units down the polygon will go into the negatives but it would still be positive because it’s going to the (-x, y) spectrum unless it’s -1,2
If you put it like 15/9 = 20/x, then cross multiply and divide you do 9 times 20 you get 180, then you divide 180 by 15 and you get 12. Hope this helps!
