## Calculus 8th Edition

Basic monthly charge $\$$35 Number of free minutes = 400 Charges for each additional minute of usage = 10 cents The monthly cost in dollars is represented by C The total number of calls is x The cost function is$C(x)= 35 \ for \ x \leq 400C(x)=35+ \frac{1}{10} (x-400) \ for \ x \gt 400\$