A sports trainer has monthly costs of $68.29 for phone service and $45.42 for his website and advertising. In addition he pays a $20 fee to the gym for each session in which he trains' a client.

A) write the function to represent the cost C(x) for x training sessions.

B) write a function representing the average cost C(x) for x sessions.

C) Evaluate C(10), C(50), C(100). Round your answer to two decimal places if necessary.