Here is what you need to find:
[tex]|-13|[/tex]
The "lines" before and after -13 is used for absolute value. Absolute value is the distance between a point and zero. Absolute value is always positive. Here are some examples:
| -500 |
↑ To find the absolute value of -500, you have to find the distance between -500 and 0, which is 500. Even if the number is negative, the absolute value is positive.
Here is another example:
| 26 |
↑ To find the absolute value of 26, you have to find the distance between 26 and 0, which is 26.
An easier way to find the absolute value of a number is to find the number that's inside | | . If the number is negative, remove the - sign. If it's positive, then the absolute value of that number is the number.
[tex]|-13|[/tex]
Remove the - sign and it becomes:
[tex]-13 \rightarrow 13[/tex]
That means your answer is 13.
