Answer:
you have to divide 12 by 15
Step-by-step explanation:
the total cost is $86.40
(0, -9) and (3,3)
(3+9)/(3-0) = 12/3 = 4
y + 9 = 4(x - 0)
y + 9 = 4x - 0
y = 4x - 9