need help stuck on hw precalculus

Question

A car rental company offers two plans for renting a car:

Plan A: 30 dollars per day and 18 cents per mile

Plan B: 50 dollars per day with free unlimited mileage

For what range of miles will plan B save you money for a 1 day rental?

To save money the mileage must be greater than    miles per day.

Give your answer accurate to at least one decimal place

Answer 1

For what range of miles will plan B save you money for a 1 day rental?

Let x = number of miles driven in a day

$30 + 0.18¢ per mile > $50

30 + .18x > 50

.18x > 20

x > 111.1 means if you drive over 111.1 miles a day, Plan B is more cost effective than Plan A

To save money the mileage must be greater than 111.1  miles per day.