Customers at a gym pay a membership fee to join and then a fee for each class they attend. Here is a graph that represents the scenario. What is the slope of the line?

Last month, leonhard euler's watch kiosk at the mall had total sales of $9,489. merchandise totaling $225 was returned. the goods that were sold cost leonhard euler's $5,481. operating expenses for the moth were $992. what was the gross profit on sales?