Chapter 10 - Exponents and Radicals - 10.7 The Distance Formula, the Midpoint Formula, and Other Applications - 10.7 Exercise Set - Page 679: 63

$d\approx10.050 \text{ units} $

Using $d=\sqrt{(x_1-x_2)^2+(y_1-y_2)^2}$ or the Distance Formula, the distance, $d$, between the given points, $\left( -1,-30 \right) \text{ and } \left( -2,-40 \right),$ is \begin{array}{l}\require{cancel} d=\sqrt{ \left(-1-(-2) \right)^2+\left(-30-(-40) \right)^2} \\\\ d=\sqrt{ \left(1 \right)^2+\left(10 \right)^2} \\\\ d=\sqrt{ 1+100} \\\\ d=\sqrt{ 101} \\\\ d\approx10.050 \text{ units} .\end{array}