Final answer:
The question pertains to algebra and the properties of straight lines on a graph, where a line with a y-intercept of 9 and a slope of 3 is represented by the equation y = 9 + 3x.
Step-by-step explanation:
The question provided delves into the subject of Mathematics, specifically focusing on algebra and the geometry of straight lines.
The line graph described with y-intercept of 9 and slope of 3 is represented by the linear equation y = 9 + 3x. Here, 9 is the y-intercept (b), indicating where the line crosses the y-axis, and 3 is the slope (m), representing the rise over run—meaning for every 1 unit increase in the x-value, the y-value increases by 3 units. To plot this line, you can create a table of values by substituting various x values into the equation and then solving for y. These points are then plotted on a Cartesian plane, and a line is drawn through them to visualize the linear relationship.