Joanne is charged a base rate of $40.00 each month for her cell service. She upgrades her phone and chooses to make 18 monthly payments of $25 to pay for her new Samsung. She must also pay 25 cents for each text that she sends. Which function represents Joanne's phone charges each month for the next 18 months?

A) y = .25x + 65
B) y = .25x + 40
C) y = .25x + 72
D) y = 25x + 40

Respuesta :

A the only one that would work because 40+25=65 and that's the only one with that option.
then D is incorrect because it's not .25 its just25
B is too low and C is too high for the ending numbers
So only A makes sense

Answer:

A) y = .25x + 65

Step-by-step explanation:

Each month Joanne will have to pay the base rate of $40.00 and the monthly payment of $25 for her new Samsung. Therefore, each month Joanne will have a fixed cost of $40+$25=$65

Then, if we set x to be the number of texts that she  sends during the month, then the cost to pay for those texts will be $0.25x since 0.25 dollars is the same as 25 cents and we multiply the unit price of a single text by the number of texts she sends.

The total charges Joannes has to pay is the sum of the fixed cost and the cost of the texts send (also called variable cost). Setting y to be that cost then the function is:

y = .25x + 65     (Notice 0.25 is the same as .25)