We'll go ahead and begin by using the graph you provided in the attached image. We can see three clear points:
(-5,-6), (0,-3), (5,0)
The slope formula is (y2-y1)/(x2-x1).
You can use the coordinates paired as [(-5,-6), (0,-3)], or [(0,-3), (5,0).
For this example, we will use the pairs (0,-3), and (5,0).
When plugging your coordinates into the formula, you should end with an equation that appears something like: (0-3)/(5-0). When solving, the slope comes out to -3/5.
Essentially, the slope is the line that crosses through two points on a graph. You can also determine the slop by counting the spaces that are over (X) and up (Y) on the graph, but that becomes tedious and sometimes impossible work depending on the scale you are working with. I hope this helped! If I explained anything in a manner that seems confusing, feel free to ask more!
