Chapter 13.2, Problem 39SR

To determine

To find: the measurement of two points $DF$ using number line.

Answer to Problem 39SR

The measurement of $DF$ is $3$ .

Explanation of Solution

Given:

  

The coordinate of $D$ and $F$ are $2$ and $5$ .

Concept used:

Distance should be put in modulus since, distance cannot be negative.

Difference in the coordinate is:

$\text{higher value-lower value}$ .

Calculation:

The coordinate of $D$ and $F$ are $2$ and $5$ .

Therefore, the statement can be written mathematical as:

  $DF=\left|5-2\right|=3.$

Hence, the measurement of $DF$ is $3$ .