A cell phone plan cost $100 to start then there is a 40 charge each month. a. what is the total cost (start up fee and monthly charge) to use the cell phone plan for one month?
b. what is the total cost for X months?
c. graph the cost of the cell phone plan over a period of two years using months as the units of time be sure to label your axis and scale then by labeling each grid line with the number.
d. is there a proportional relationship between time in the cost of the cell phone plan ?explain how you know.