Final answer:
The correct expression to calculate the unit rate of miles per gallon from the given information is B. 315 miles ÷ 15 gallons, which is the standard way to express fuel economy for a car. The correct expression is:B. 315 miles ÷ 15 gallons
Step-by-step explanation:
To determine the unit rate of miles per gallon for a car that uses 15 gallons of gasoline when driven 315 miles, the correct expression is B. 315 miles ÷ 15 gallons. This expression will give you the number of miles the car can travel on one gallon of gasoline, which is the standard way to express fuel economy. It is important to ensure that miles are in the numerator and gallons in the denominator, as we want to calculate the mileage per single gallon of gasoline used.
To determine the unit rate of miles per gallon of gasoline, you need to express the relationship between miles and gallons. The correct expression is:
B. 315 miles ÷ 15 gallons
This expression represents the number of miles traveled per gallon of gasoline, giving the unit rate in miles per gallon.