We will have the following:
[tex]|5(15)-(-5)|=80[/tex]***Explanation***
We have that absolute value is used in order to obtain magnitudes, and since magnitudes are positive those are the values we are going to obtain.
Now, for example:
|5| = 5
|-5| = 5
|420| = 420
|-69| = 69
|342| = 342
|-23| = 23
This is the nature of the absolute value, it gives us the positive value and thus the magnitude (In other words it removes the "direction" the value had.)
