The price for footballs is displayed in the graph. Derive the equation of the proportional relationship through the origin

Answer 1

To derive the equation of the proportional relationship through the origin, we need to determine the slope of the graph.

Let's take two points from the graph: (3, 15) and (6, 30).

The formula for calculating the slope between two points (x1, y1) and (x2, y2) is:
slope = (y2 - y1) / (x2 - x1)

Using the points (3, 15) and (6, 30), we can substitute into the formula:
slope = (30 - 15) / (6 - 3)
slope = 15 / 3
slope = 5

Since the proportional relationship goes through the origin, the y-intercept is 0.

Therefore, the equation of the proportional relationship through the origin is:
y = 5x