9. A cleaning service, C, charges a fixed cost of $15 plus a rate of $30 per hour for the length of the
service, and another cleaning service, D, charges a fixed cost of $40 plus a rate of $20 per hour.
(a) Write a function C(t) and a function D(t) that represent the situation.

C(t)= 15 + 30t

D(t)= 40 + 20t

Step-by-step explanation:

Fixed cost means that a customer will pay that no matter what, the per hour charge is the only thing that will change.

i think 1: 2

step-by-step explanation:

answer: the price of one pound cabbage = $ 0.8

the point (10,8) represents that the cost of 10 pounds cabbage is $ 8

step-by-step explanation:

since, here is a proportional relation between the number of pounds of cabbage (x) and the price in dollars (y).

therefore, we can write,

⇒ y = k x

where k is the constant of proportionality.

now, point (5,4) is in the line.

thus, it will satisfies the above equation of line.

⇒ 4 = 5 k

⇒ k = 0.8

thus, the equation of the line is,

y = 0.8 x

a) for x = 1,

y = 0.8

therefore, the cost of one pound of cabbage is 0.8 dollars.

b) in the below graph (10,8) represents that the cost of 10 pounds of cabbage is 8 dollars.