Final answer:
In the equation y = 25 + 20x, the independent variable is the number of hours of work, the dependent variable is the total amount of money Ethan earns per visit, the y-intercept is $25, and the slope is $20 per hour of work.
Step-by-step explanation:
The independent variable in the equation y = 25 + 20x is the number of hours of work, represented by x. The dependent variable is the total amount of money Ethan earns per visit, represented by y. The y-intercept of the equation is 25, which means that even if Ethan doesn't do any work, he still charges a flat fee of $25. The slope of the equation is 20, which means that for every hour of work, Ethan charges an additional $20. This can be interpreted as the cost per hour of work.