What is the factor rainbow of 42

Name the most appropriate metric unit for each measurement like the mass of cow

Omar is going on a road trip! the car rental company offers him two types of cars. each car has a fixed price, but he also needs to consider the cost of fuel. the first car costs $90 to rent, and because of its fuel consumption rate, there's an additional cost of s0.50 per kilometer driven.

Is this a polynomial function? i need to know asap