Answer:
The amount of gas the car used is;
[tex]3.5\text{ gallons}[/tex]Explanation:
Given the equation;
[tex]m=40g[/tex]where;
m = distance in miles that a car can travel using g gallons of gas.
If the car has gone 140 miles ;
[tex]m=140\text{ miles}[/tex]Substituting the value of m;
[tex]\begin{gathered} 140=40g \\ g=\frac{140}{40} \\ g=3.5\text{ gallons} \end{gathered}[/tex]Therefore, the amount of gas the car used is;
[tex]3.5\text{ gallons}[/tex]