First, remember that the formula for the slope of a line between two points is
[tex] \frac{ y_{2} - y_{1} }{ x_{2} - x_{1} } [/tex]
Let's choose two coordinates, (-2,13) and (3,-7), and substitute them into the formula and simplify for the gradient:
[tex] \frac{ - 7 - 13}{3 - - 2} = \frac{ - 20}{5} = - 4[/tex]
So, the slope of the function is -4.
