Carolina receives an allowance that is tied to completing her chores during the week. She starts off with an allowance of $20. She has five chores to complete during the week, and for each chore she completes, she receives $3. However, for each chore that is not done by the end of the week, she loses $4 from her allowance. a. Write an expression describing Carolina's allowance as a function of the number of chores, C, that she completes during the week.

b. If Carolina completes 4 chores, what is her allowance?