Question

A family has 2 cars. the first car has a fuel efficiency of 15 miles per gallon of gas and the second has a fuel efficiency of 20 miles per gallon of gas. during one particular week, the 2 cars went a combined total of 1300 miles, for a total gas consumption of 75 gallons. How man gallons were consumed by each of the cars that week?
car 1 :
car 2:

Answer 1

Car 1: 15x

Car 2: 20y

15x+20y=1300

x+y=75

So y=75-x

15x+20(75-x)=1300

-5x+1500=1300

-5x=-200

x=40.

y=75-40

y=35

Car 1: 40 gallons

Car 2: 35 gallons