The slope is the steepness of the line. To find it, you divide how far up it goes by how far across it goes. This equals the diagonal incline. To find it with points, you find the difference between the y values and divide that by the difference in the x values!
-9-6=-15
10-1=9
-15/9=-15/9
This slope means that for every nine units the line goes across, it goes down 15 units!