Answer :
Let's define the following variables.
x = fuel efficiency of Car 1
y = fuel efficiency of Car 2
Therefore, 40x + 15y = a total of 1975 miles.
Another given data is that the sum of the fuel efficiency of the two cars is 65 miles per gallon, therefore, x + y = 65.
We now have two equations:
1. 40x + 15y = 1975
2. x + y = 65
To solve for x and y, let's use the substitution method. Let's equation the second equation into y. So, equation 2 becomes y = 65 - x. Using this, we'll substitute the value of y in the first equation,
[tex]\begin{gathered} 40x+15y=1975 \\ 40x+15(65-x)=1975 \\ 40x+975-15x=1975 \\ 40x-15x=1975-975 \\ 25x=1000 \\ \frac{25x}{25}=\frac{1000}{25} \\ x=40 \end{gathered}[/tex]Therefore, the fuel efficiency of Car 1 is 40 miles per gallon.
Since we now have the value of x, let's solve for the value of y.
[tex]\begin{gathered} y=65-x \\ y=65-40 \\ y=25 \end{gathered}[/tex]Therefore, the fuel efficiency of Car 2 is 25 miles per gallon.