## Elementary Algebra

Let X represent the distance the car will travel on 15 gallons. Now, let’s set up a proportion in which one ratio compares the amounts of gasoline and the other ratio compares the corresponding distance the car can travel. So, $\frac{12}{15}$ = $\frac{264}{X}$ We cross multiply to obtain: 15 $\times$ 264 = 12 $\times$ X 3960 = 12X Divide both sides by 12 X = 330 The car will travel 330 miles on 15 gallons.