Here is the solution...
This is a proportional relationship.
A proportional relationship is nothing the two quantities vary directly with each other.
The proportional equation y = k x. where k is the constant proportionality.
This means that as x increases, y increases and as x decreases, y decreases.
Here we use the proportional relationship to find the equation.
The number of miles driven is proportional to the number of gallons of gas.
Therefore, the equation is Miles = k Gallons
That is M = k G, where k represents the number of miles driven per gallon of gas.
