Suppose you write a book. the printer charges $4 per book to print it, and you spend $5500 on advertising. you sell the book for $15 a copy. how many copies must you sell to break even (total cost equals income for sales)? what is your income (or costs) for that many copies?

Ian is in training for a national hot dog eating contest on the 4th of july. on his first day of training, he eats 4 hot dogs. each day, he plans to eat 110% of the number of hot dogs he ate the previous day. write an explicit formula that could be used to find the number of hot dogs ian will eat on any particular day.