Final answer:
The relationship uses addition as part of a linear equation that involves both addition and multiplication to define the relationship between two variables graphically.
Step-by-step explanation:
The relationship described in the question uses addition as part of a linear equation. A linear equation such as y = b + mx involves both addition and multiplication, where b is the y-intercept and mx denotes the slope m multiplied by the variable x.
To express these equations graphically, we plot the resulting values on a coordinate plane, creating a straight line that represents the relationship between x and y. Professionals use linear equations to understand and predict relationships between variables, such as exam scores in academic settings.