What is a rate in which the second quantity is one unit?

Acredit card advertises an annual interest rate of 23%. what is the equivalent monthly interest rate?

What is the rate of change of a line that passes through (2,-5) and (6,-2)?

Part a: sam rented a boat at $225 for 2 days. if he rents the same boat for 5 days, he has to pay a total rent of $480. write an equation in the standard form to represent the total rent (y) that sam has to pay for renting the boat for x days. (4 points)