A cell phone plan costs $20 a month and includes 200 free minutes. Each additional minute costs 5 cents. If you use your cell phone for at least 200 minutes a month, write a function C(x) that represents the total cost per x minutes.
We add the flat rate per month to 5% of the number of minutes over 200:
C(x) = 20 + 0.05(x - 200)
We add the flat rate per month to 5% of the number of minutes over 200:
C(x) = 20 + 0.05(x - 200)