[tex]\bf slope = {{ m}}= \cfrac{rise}{run} \implies
\cfrac{{{ f(x_2)}}-{{ f(x_1)}}}{{{ x_2}}-{{ x_1}}}\impliedby
\begin{array}{llll}
average\ rate\\
of\ change
\end{array}
\\\\\\
f(x)=x^3-3x-5\quad
\begin{cases}
x_1=2\\
x_2=8
\end{cases}\implies \cfrac{f(8)-f(2)}{8-2}[/tex]