[tex]f(x) = \dfrac{x+1}{x^2-7x-8} \\~\\~\\f(x) = \dfrac{x+1}{(x-8)(x+1)} \\~\\~\\f(x) = \dfrac{1}{x-8}[/tex]
[tex]\text{avg} = \dfrac{f(a)-f(b)}{a-b} \\~\\~\\\text{avg} = \dfrac{\left(\dfrac{1}{3-8}\right)-\left(-\dfrac{1}{2+8}\right)}{3-(-2)} \\~\\~\\\text{avg} = \dfrac{\left(\dfrac{1}{-5}\right)-\left(-\dfrac{1}{10}\right)}{5} \\~\\~\\\text{avg} = \dfrac{1}{2}-1 \\~\\~\\ \text{avg} = -\dfrac{1}{2}[/tex]
