First, find the coordinates of each point looking to the graph.
1) Point T: (-5,0)
2) Point R: (1,2)
3) Point S: (7,4)
Use the slope formula to find the slope for each pair of points:



Therefore, the slope of TR, RS and TS is 1/3.
7) The slope of the line is constant and equal to 1/3.
8) The constant rate of change of the line is 1/3.