[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)= \qquad
\begin{cases}
x_1=1\\
x_2=2
\end{cases}\implies \cfrac{f(2)-f(1)}{2-1}[/tex]
