Answer:
7 gallons were used for city driving.
Step-by-step explanation:
I am going to solve this question by a system of equations.
I am going to say that:
x is the number of gallons driven in the city.
y is the number of gallons driven in the highway.
19 gal of gas
This means that [tex]x + y = 19[/tex]
Carole's car averages 13.2 mi/gal in city driving and 25.3 mi/gal in highway driving. If she drove a total of 396.0 mi.
This means that [tex]13.2x + 25.3y = 396[/tex]
How many of the gallons (to the nearest gallon) were used for city driving?
This is x
From the first equation, i will have
[tex]y = 19 - x[/tex]
Replacing in the second equation
[tex]13.2x + 25.3y = 396[/tex]
[tex]13.2x + 25.3(19 - x) = 396[/tex]
[tex]13.2x - 25.3x = 396 - 480,7[/tex]
[tex]12.1x = 84.7[/tex]
[tex]x = \frac{84.7}{12.1}[/tex]
[tex]x = 7[/tex]
7 gallons were used for city driving.
