[tex]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}\\\\[-0.35em] \rule{34em}{0.25pt}\\\\ g(t)= 20.9t\qquad \begin{cases} t_1=2\\ t_2=3 \end{cases}\implies \cfrac{g(3)-g(2)}{3-2}\implies \cfrac{20.9(3)~~ - ~~20.9(2)}{1} \\\\\\ 62.7~~ - ~~41.8\implies 20.9[/tex]
