Paul made flyers to promote the grand opening of his bookstore. He gave 20 flyers to his friends, and then handed out 9 flyers every hour. He decides to graph the number of flyers, y, given out over x hours. Which equation best describes Paul's graph?

For this case, the first thing we must do is define variables.
 We have then:
 x: number of hours.
 y: number of flyers
 We now write the equation that represents this problem.
 We have then:
 y = 9x + 20
 The slope of the graph m = 9 represents the number of flyers distributed every hour.
 The intersection with the axis and b = 20 represents the number of flyers that Paul distributed to his friends.
 Answer:
 An equation that best describes Paul's graph is:
 y = 9x + 20