troy's truck has a 30 gallon gas tank and gets an average of 21 miles per gallon.write an equation to represent the amount of gas in troy' s truck after driving a certain number of miles (assuming he starts with a full tank).define your variables.
So, 30 gallons, and 21 miles per gallon. Lets say, the variable for the miles he can travel is x. What is x? x is 30 gallons that allow for 21 miles to be traveled for each, so it would be written like this.
