Question

The equation c = 6.25n + 20 gives the dollar cost, C, of renting a jet-ski for n hours.

a) If the cost is $70, how many hours was the jet-ski rented for?
b) write an equation that represents the inverse function: the number of hours, n, as a function of the cost, c.

Answer 1

a) The jet-ski was rented for 8 hours.

b) The inverse function is n = (c - 20)/6.25.

Step-by-step explanation:

a) To find the number of hours the jet-ski was rented for, we can substitute the given cost of $70 into the equation and solve for n:
C = 6.25n + 20
70 = 6.25n + 20
50 = 6.25n
n = 50/6.25
n = 8

Therefore, the jet-ski was rented for 8 hours.

b) The inverse function represents the number of hours, n, as a function of the cost, c.

To find this, we can rewrite the equation:
c = 6.25n + 20
Subtract 20 from both sides of the equation:
c - 20 = 6.25n
Divide both sides of the equation by 6.25:
(c - 20)/6.25 = n
So, the inverse function is n = (c - 20)/6.25