8th Grade Math Problem

Question

Maximilian wants to rent a car for 10 days, and he has two options. The first rental car company charges a $35 rental fee and an amount of $110 for 3 days. The second rental car company's offer can be modeled by the equation y=28x+15, where x is the number of days and y is the total cost of renting a car.

Which rental car company (first or second) is the better option and why?

Answer 1

If you simply create an equation from the first option, you would find that the constant value (or y-intercept) is $35, and if the company charges $110 for 3 days, then that means they charge ($110/3), or $36.67 per day. This would cause the equation to be y=36.67x+35, and we already know the second equation to be y=28x+15. Therefore, all we have to do is plug in the value x=10 to each equation and find which one value is lower to indicate a better price. The first option has a value of 36.67(10)+35, or $401.70. The second equation gives us a cost of 28(10)+15, or $295. The second option is cheaper than the first, making it the better option for Maximilian to choose.