Final answer:
The second train, represented by the equation y = 6.5x, has a fuel usage rate of 6.5 gal/mi. This rate is higher than the first train's rate of 6 gal/mi, so the second train uses fuel at a greater rate.
Step-by-step explanation:
The student's question pertains to the fuel usage rate of two trains, which is a concept in mathematics, specifically in algebra where equations are used to represent real-world situations. The first train uses fuel at a constant rate of 6 gallons per mile (gal/mi). The equation y = 6.5x presumably describes the second train’s fuel usage with y representing the total gallons of fuel used and x representing the miles traveled, suggesting that the second train uses fuel at a rate of 6.5 gal/mi.
Therefore, comparing the two rates, the first train's fuel usage is 6 gal/mi, and the second train's fuel usage is 6.5 gal/mi. So, the second train uses fuel at a greater rate than the first train.