Question

is the total cost to fill a car gas tank a direct or inverse variation with respect to the number of gallons used ?...​

Answer 1

Answer: Direct variation

Step-by-step explanation:

Let y represent the total cost and x represent the number of gallons.

Assume gas cost $5 per gallon.  How would you decide how much to pay?

y = 5x   -->    $\dfrac{y}{x}=5$ which is direct variation