The fuel efficiency rating for a certain car is 28 miles per gallon on the highway and 21 miles per gallon in the city. During one week the car traveled a total of 10.5 gallons of fuel.

a) please set up an equation(s) that would model the situation.(be sure to identify variables.)

b) how much fuel was used for highway driving? (round your answer to the nearest tenth of a gallon.)

c) how many miles where driven on the highway?( round your answer to the nearest tenth of a mile.)