The graph above shows the distance traveled d, in feet, by a product on a conveyor belt m minutes after the product is placed on the belt. Which of the following equations correctly relates d and m?

Explanation

Choice A is correct. The line passes through the origin. Therefore, this is a relationship of the form d = km, where k is a constant representing the slope of the graph. To find the value of k, choose a point (m, d) on the graph of the line other than the origin and substitute the values of m and d into the equation. For example, if the point (2, 4) is chosen, then 4 = k(2), and k = 2. Therefore, the equation of the line is d = 2m.