Final answer:
The number of gallons of gas remaining in the tank can be calculated by subtracting the gallons of gas consumed during the trip from the total gallons of gas initially in the tank and adding the gallons of gas refueled at the gas station.
Step-by-step explanation:
The number of gallons of gas remaining in the tank can be calculated by subtracting the gallons of gas consumed during the trip from the total gallons of gas initially in the tank and adding the gallons of gas refueled at the gas station. Therefore, the correct expression is:
x - y + z