Question 4 A family has two cars. The first car has a fuel efficiency of miles per gallon of gas and the second has a fuel efficiency of miles per gallon of gas. During one particular week, the two cars went a combined total of miles, for a total gas consumption of gallons. How many gallons were consumed by each of the two cars that week

Complete question is;

A family has two cars. The first car has a fuel efficiency of 35 miles per gallon of gas and the second has a fuel efficiency of 40 miles per gallon of gas. During one particular week, the two cars went a combined total of 1850 miles, for a total gas consumption of 50 gallons. How many gallons were consumed by each of the two cars that week?

Car 1 consumed 30 gallons of gas.

Car 2 consumed 20 gallons of gas.

Step-by-step explanation:

Let x be number gallons consumed by car 1

Let y be number of gallons consumed by car 2

We are told that total gas consumption of 50 gallons. Thus;

x + y = 50 - - - - - eq(1)

We are told that the first car has a fuel efficiency of 35 miles per gallon of gas and the second has a fuel efficiency of 40 miles per gallon of gas and they went a combined total of 1850 miles. Thus;

35x + 40y = 1850 - - - - eq2

Let's make y the subject in eq(1),

y = 50 - x - - - - eq(3)

Putting 50 - x for y in eq 2 gives;

35x + 40(50-x) = 1850

35x + 2000 - 40x = 1850

-5x + 2000 = 1850

-5x = -150

x = 150/5

x = 30 gallons

Substitute 30 for x into eq 3,we have;

y = 50 - 30

y = 20 gallons

Thus;

Car 1 consumed 30 gallons of gas.

Car 2 consumed 20 gallons of gas.