Question

The equation f(g)=40g gives the distance in miles, f(g), that a car can travel using g gallons of gas. If the car has gone 180 miles, how much gas was used?

Answer 1

4.5

Explanation:

Since the slope of the equation is 40, we know that for every gallon of gas used, the car travels 40 miles. We know that in total he traveled 180 mi, so if we divide 40 into 180 we can find out how many gallons of gas he used.

180 / 40 = 4.5

so 4.5 gallons of gas were used. To check our work we can just substitute it back into the equation

40 x 4.5 = 180

This equation is true, so now we know that 4.5 gal of gas was used in total. I hope this helps you out :)