Christopher spent a total of $52.50 at a bookstore. He purchased a calendar for $9 and three books that each cost the same amount. Which of the following equations could be used to find b, the amount of each book he purchased?

The answer would be c

This is what i found “an explicit formula designates the nth term of the sequence, as an expression of n (where n = the term's location). it defines the sequence as a formula in terms of n. this example is an arithmetic sequence(the same number, 5, is added to each term to get to the next term).” i hope this you for what your looking for. can you plz mark me brainliest?