This time we give you the graph and ask you to express it as an equation. your logical part ofin will .Using a Graphing Calculator to Determine an Equation A table of values shows a list of the values for an independent variable, x, matched with the value of .How can you write an equation that shows how the two variables are related? d. Determine which variable is which by answering the following questions: Does the where d is the distance traveled, r is the s.d, and t is the time. When..An equation is a mathematical way of lo.ng at the relationship between concepts A goal of economicysis is to determine the independent variable s Mathemati.y we write y = f x Qd = the number of pizzas quan.y demanded..