The slope of a line in the context of a linear equation like y = mx + b represents the rate at which y changes with respect to x. In this equation, y represents the cost to rent skates and x represents the number of hours the skates are rented.
The coefficient m, which is the number multiplying x, is the slope of the line. In the given equation y = 2.50x + 5, the slope is 2.50. This indicates that for every increase of one unit in x (for every additional hour the skates are rented), the value of y (the total cost to rent the skates) increases by 2.50 units (2.50 dollars).
As a result, the slope of the line (2.50) tells us how much the cost to rent the skates increases per hour, which means it represents the cost per hour to rent the skates.
Therefore, the correct answer to what the slope of this line represents is:
(B) the cost per hour to rent the skates
