An investor invests $525 in stock. For the first six months, the stock increased at a rate of $25 per month.

Identify the slope of the linear relationship. Explain what this means in the context of the problem.
Identify the y-intercept of the linear relationship. Explain what this means in the context of the problem.
Create a model in slope intercept form to represent the total value of the stock, f(x), based on the number of months, x.