Final answer:
Sam earns $89 in a week when he sells 33 books, calculated by the function A(b) = 56 + b, where b represents the number of books sold.
Step-by-step explanation:
The student wants to know how much Sam earns in a week when he sells 33 books at the bookstore, where he works part-time and earns $56 base pay plus an additional $1 for each book sold.
To find out Sam's total earnings, we need to substitute the number of books (b) into the given function A(b) = 56 + b. In this case, the number of books (b) is 33, so we calculate A(33) = 56 + 33, which equals $89. Therefore, Sam earns $89 in a week when he sells 33 books.