SOLUTION: In a family there are two cars. In a given week, the first car gets an average of 40 miles per gallon, and the second car gets 35 miles per gallon. The two cars combined drive a to
Algebra ->
Coordinate Systems and Linear Equations
-> SOLUTION: In a family there are two cars. In a given week, the first car gets an average of 40 miles per gallon, and the second car gets 35 miles per gallon. The two cars combined drive a to
Log On
Question 175999: In a family there are two cars. In a given week, the first car gets an average of 40 miles per gallon, and the second car gets 35 miles per gallon. The two cars combined drive a total of 1300 miles in that week, for a total gas consumption of 35 gallons. How many gallons were consumed by each of the two cars that week?
You can put this solution on YOUR website! n a family there are two cars. In a given week, the first car gets an average of 40 miles per gallon, and the second car gets 35 miles per gallon. The two cars combined drive a total of 1300 miles in that week, for a total gas consumption of 35 gallons. How many gallons were consumed by each of the two cars that week?
:
Let x = no. of gallons consumed by the 1st car
Let y = no. of gallons consumed by the 2nd
:
Total gallons equation:
x + y = 35
or
y = (35-x); use this for substitution
:
Miles driven equation
40x + 35y = 1300
Substitute (35-x) for y
40x + 35(35-x) = 1300
40x + 1225 - 35x = 1300
40x - 35x = 1300 - 1225
5x = 75
x =
x = 15 gal used by the 1st car
and
35 - 15 = 20 gal used by the 2nd car
:
:
Check solution in the miles equation
40(15) + 35(20) =
600 + 700 = 1300 mi confirms our solutions
