45 books in 5 shelves = books per shelf

What is the slope simplify your answer and write it as a proper fraction, improper fraction, or integer

12. the amount of money in a bank account decreased by 21.5% over the last year. if the amount of money at the beginning of the year is represented by ‘n', write 3 equivalent expressions to represent the amount of money in the bank account after the decrease?

It says factor each expression completely 8y+48