Use the equation for the slope:
[tex] slope = \frac{y2-y1}{x2-x1} [/tex]
The two points are equal to (x1, y1) and (x2, y2).
So choose one of your points to be (x1, y1). Let's choose (4, -2). That means x1 = 4 and y1 = -2.
The other point would then be (x2, y2). So x2 = 24 and y2 = -17.
Now put these values in to the equation:
[tex] Slope = \frac{-17-(-2)}{24-4} = \frac{-15}{20} = \frac{-3}{4}[/tex]
The slope is -3/4.
