I give up on math. help.

What properties allow transformation to be used as a problem solving tool

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.

What is the value of x? enter your answer in the box.