Question

what is the length of $overline{mn}$?

Explanation:

Step1: Identify coordinates

The coordinate of point $M$ is $- 10$ and the coordinate of point $N$ is $-6$.

Step2: Use distance formula on number - line

The distance $d$ between two points $x_1$ and $x_2$ on a number - line is $d=\vert x_2 - x_1\vert$. Here, let $x_1=-10$ and $x_2 = - 6$. Then $d=\vert-6-(-10)\vert$.

Step3: Simplify the expression

$\vert-6 + 10\vert=\vert4\vert = 4$.

Answer:

$4$