Final answer:
To travel 750 miles using the equation D = 30G, you would need 25 gallons of gas.
Step-by-step explanation:
To determine the number of gallons of gas needed to travel 750 miles using the equation D = 30G, we can rearrange the equation to solve for G. Dividing both sides of the equation by 30, we get G = D/30.
Substituting the given distance of 750 miles, we have G = 750/30 = 25.
Therefore, you would need 25 gallons of gas to travel 750 miles.