If a car rental company charges $7 a day and 9 a mile to rent one of its cars, then the cost z, in dollars, to rent a
car for 2 days and drive y miles can be found from the equation

z = 7x + 0.09y

a. How much does it cost to rent a car for 4 days and drive it for 280 miles under these conditions? It costs $__

b. A second company charges $10 a day and 7¢ a mile for the same car. Write an equation that gives the cost z,
in dollars, to rent a car from this company for a days and drive it y miles.

Z=___

c. A car is rented from each of the companies for 2 days. To find the mileage at which the cost of renting the
cars from each of the two companies will be equal, solve the following system for y:

z= 7x + 0.09y
Z= 102 +0.07y
H= 2

y=____ miles