Five billion, twenty-four million, five and six thousandths

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.

Ijust need these 2 questions answered (the second pic is just confirmation i'm not confident in that answer)

Find the maximum value of p= 4x + 5y subject to the following constraints :