Hans purchased a prepaid phone card for $45.50. Calls cost
7 cents a minute using this card. The credit, C(in dollars), left on the card after it is used for x minutes of calls is given by the following function.
C(x)=45.50-0.07x
How much credit is left on the card after Hans uses it for
30 minutes of calls?
1 answer
just substitute in 30 for x and evaluate the number.
2 answers