Question

David drove 232 miles in 4 hours and 319 miles in 5.5 hours. What is the constant rate of change?

Answer 1

$\bf \begin{array}{ccll} hours&miles\\ \cline{1-2} 4&232\\ 5.5&319 \end{array}~\hspace{10em} (\stackrel{x_1}{4}~,~\stackrel{y_1}{232})\qquad (\stackrel{x_2}{5.5}~,~\stackrel{y_2}{319}) \\\\\\ slope = \cfrac{\stackrel{rise}{ y_2- y_1}}{\stackrel{run}{ x_2- x_1}}\implies \cfrac{319-232}{5.5-4}\implies \cfrac{87}{1.5}\implies 58\frac{mi}{hrs}\impliedby \textit{rate of change}$