#### Answer

$d\approx2.236
\text{ units}
$

#### Work Step by Step

Using $d=\sqrt{(x_1-x_2)^2+(y_1-y_2)^2}$ or the Distance Formula, the distance, $d$, between the given points, $(
-1,-4
) \text{ and } (
-3,-5
),$ is
\begin{array}{l}\require{cancel}
d=\sqrt{(-1-(-3))^2+(-4-(-5))^2}
\\\\
d=\sqrt{(2)^2+(1)^2}
\\\\
d=\sqrt{4+1}
\\\\
d=\sqrt{5}
\\\\
d\approx2.236
\text{ units}
.\end{array}