Q: a cell phone company charges $60.00 a month for up to 1 gigabyte of data. the cost of additional data is $0.05 per megabyte. if d represents the number of additional megabytes used and c represents the total charges at the end of the month, which linear equation can be used to determine a user's monthly bill?
possible answers: a. c = 60 - 0.05d , b. c = 60.05d , c. c = 60d - 0.05 , d. c = 60 + 0.05d