I think it’s positive. As it gets heavier, the cost has a positive slope, or increases. I’m not absolutely sure though
RS is 68 and T is 92 if you want an explanation then i gotten but u said quick so maybe it is timed idk
-x^2 + 4x + 12 = -3x + 24
-> x^2 - 7x + 12 = 0
-> (x-3)(x-4) = 0
-> x= 3 or 4
so y = 15 when x = 3, y = 12 when x = 4