Absolute Value basics

[revoltangel]

I need help knowing the basic rule of absolute values. I've always been taught that anything inside the " | x | " absolute value sign always comes out positive. I am learning that is not always the case. What should I know about absolute value when it comes to the GMAT? Thx

[cramya]

Revolt,

|x| is never negative

By defnition:

If x is positive or 0 then |x| = x

If x is neagtive then |x| = -x (negative(negative) = positive here x is negative)

Eg:

Let x=-2


|x| = |-2| by defnition = - x = - (- 2) = 2

I am learning that is not always the case

Can u help me understand what u meant above just so we are on the same page?

[Ian Stewart]

Revolt,

|x| is always positive

Well, that's almost true: |x| can also be equal to zero. Of course, absolute value measures a distance, so it can never be negative.

[cramya]

Good catch Ian!

I should have put it as |x| is never negative like u have mentioned(edited it above and added 0).