To find the slope, you must select 2 of those points.
For examp,le lets say (-5,2) is x1 and y 1, and (-1,8) is x2, and y2
To find the slope you must subtract x2-x1, and y2-y1, then divide x by y
think of it as
[tex]\frac{x2-x1}{y2-y1}[/tex]
Thats your formula.
Glad i can help
