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A family has two cars. The first car has a fuel efficiency of 15
miles per gallon of gas and the second has a fuel efficiency of 25
miles per gallon of gas. During one particular week, the two cars went a combined total of 825
miles, for a total gas consumption of 45
gallons. How many gallons were consumed by each of the two cars that week?

Respuesta :

Answer:

We set up our equations:

 

35x+40y = 1850        eq1

x+y = 50                   eq2

 

Substituting eq 2 into eq 1,

 

35x+40(50-x) = 1850

35x+2000-40x = 1850

-5x+2000 = 1850

-5x = -150

  x = 30

 

Substitute value of x into eq 2.

 

x+y = 50

30+y = 50

     y = 20

 

Car 1 consumes 30 gallons of gas.

Car 2 consumes 20 gallons of gas.

hope this helps



35x+40y = 1850        eq1

x+y = 50                   eq2