SOLUTION: A family has two cars. The first car has a fuel efficiency of 20 miles per gallon of gas and the second has a fuel efficiency of miles30 per gallon of gas. During one particular we

Algebra ->  Human-and-algebraic-language -> SOLUTION: A family has two cars. The first car has a fuel efficiency of 20 miles per gallon of gas and the second has a fuel efficiency of miles30 per gallon of gas. During one particular we      Log On


   

Question 1114402: A family has two cars. The first car has a fuel efficiency of 20 miles per gallon of gas and the second has a fuel efficiency of miles30 per gallon of gas. During one particular week, the two cars went a combined total of 1550 miles, for a total gas consumption of 60 gallons. How many gallons were consumed by each of the two cars that week?
Answer by josgarithmetic(39617) About Me  (Show Source):
You can put this solution on YOUR website!
%28fuelEfficiency%29%2A%28volume%29=%28distance%29

R%2AV=D
D%2FV=R 

CAR              Fuel Rate    Volume     Distance

FirstCar          20          60-x       20(60-x)

SecondCar         30           x          30x

Totals                        60          1550

See the way the variable usage is shown and assigned.

A useful equation is the sum of the distances:
highlight_green%2820%2860-x%29%2B30x=1550%29