Question

The cost, in dollars, of a one-day car rental is given by C(x) = 31 + 0.18x, where x is the number of miles driven. In this function,
A) $0.18 is the cost per day to rent the car and $31 is the cost per mile.
B) $31 is the cost per day to rent the car and $0.18 is the cost per mile.
C) $18 is the cost per day to rent the car and $0.31 is the cost per mile.
D) $31 is the cost per day to rent the car and $18 is the extra cost for unlimited miles.
*please explain how you got your answer, i know the answer i just dont understand how to get it. if that makes sense*

Answer 1

It's pretty simple. With every mile, the cost of rent increases by $0.18. And $31 is fixed regardless of the distance the car is driven. So that $31 counts as the fixed per day charge.
For example if you're to rent the car for 100 miles, you've to pay
C(100) = 31(fixed for day) + 0.18 *100 (for 100 miles) = $49

Answer 2

hey could you help me understand how to do F(X) problems as a whole please. I would be really grateful. <3

Answer 3

An F(x) is a function. F() is the name of the function and x is any variable. What a function does is, it takes a value, any value which is x=100 in the above example, and processes it and gives a result. In this case the function is C() which takes in the number of miles driven by the car and after computation, that is after substituting the value 100 in place of x, we get the rent.

Answer 4

so i understand like how you replace the X's with a real number but my question is what if they don't tell you what number to insert in place of X

Answer 5

The number doesn't matter.. It's the way the number has to be processed that matters. Functions tell you how to process a real value to get a result.

Answer 6

okay so then for the question at the top what would i have plugged in if i were looking for the actual answer.

Answer 7

You need to know the miles driven before you can get the cost.. For this specific question you don't need the actual cost or cost of a specific number of miles. Here you only have to tell 1. the fixed rent per day, 2. the rent per mile. The actual cost can be calculated after the user returns the car by taking the miles driven and calculating the result using the function C()

Answer 8

oh okay thank you sooo much for your help.

Answer 9

you are a real life saver