Question

Cathy pays $25 a month plus $0.05 per text message. She models this with the function C = 0.05x + 25. If the text messaging fee increases to $0.10, what is her new function?

Answer 1

C=0.10x+25
nothing changes except the monthly fee so just replace the old with the new

Answer 2

`C=0.10x+25`

Explanation:

1. The current function which express the fee that Cathy pays is the following:

`C=0.05x+25`

where $0.05 is the payment per text message, $25 is the payment a month and x is the quantity of text messages.

2. If the text messaging fee increases to $0.10 the change in the function will be:

`C=0.10x+25`

it means that for each text message Cathy will pay $0.10 and the montly fee remains the same.