Final answer:
The subject of this question is Mathematics and the grade level is High School. The equation y = 12500 + 10x represents the total monthly income of the salesman in relation to his sales. The independent variable is x (sales) and the dependent variable is y (total monthly income). The y-intercept is 12500 (fixed salary) and the slope is 10 (additional earning per unit of sales).
Step-by-step explanation:
The subject of the question is Mathematics.
The grade level of the question is High School.
The given equation is y = 12500 + 10x.
Here, y represents the total monthly income of the salesman, and x represents his sales.
The independent variable in this equation is x, which is the sales. The dependent variable is y, which is the total monthly income.
The y-intercept is 12500, which represents the fixed salary of the salesman. The slope is 10, which represents the additional earning for every unit of sales. It means that for every unit increase in sales, the salesman's monthly income increases by 10.