The graph that represents the line y=15x is the first one: "A line graphed on a coordinate plane with x and y axis ranging from negative 5 to 5. The line passes through the origin and begin ordered pair 5 comma 1 end ordered pair." This is because the equation y=15x represents a line with a slope of 15 and passing through the origin. The first graph fits this description, as it passes through the origin and the ordered pairs on the line have a slope of 15.