Chapter 9 - Section 9.1 - Solving Quadratic Equations by the Square Root Property - Exercise Set - Page 632: 51

$d=17 \text{ units} $

Using $d=\sqrt{(x_1-x_2)^2+(y_1-y_2)^2}$ or the Distance Formula, then the distance, $d$, between the given points $( -4,2 )$ and $( 4,17 )$ is \begin{array}{l}\require{cancel} d=\sqrt{(-4-4)^2+(2-17)^2} \\\\ d=\sqrt{(-8)^2+(-15)^2} \\\\ d=\sqrt{64+225} \\\\ d=\sqrt{289} \\\\ d=\sqrt{(17)^2} \\\\ d=17 \text{ units} .\end{array}