1. ## Simplify a Negative

Ok, it says -(-10) is 10, which I get, but why does -|-5.2| = -5.2? I thought || were the same as ()

2. Originally Posted by Jarod_C
Ok, it says -(-10) is 10, which I get, but why does -|-5.2| = -5.2? I thought || were the same as ()
The $\displaystyle |x|$ is the modulus of $\displaystyle x$ and it is always positive so...

$\displaystyle -|-5.2| = - |5.2| = -5.2$

Whereas $\displaystyle (x)$ are just brackets and do not change the value of $\displaystyle x$ inside so...

$\displaystyle -(-10) = - - 10 = 10$ (It's a minus of a negative number so makes it positive).

3. thanks for the fast reply, how about [x]? I guess I should ask now instead of when it comes up in the future.

Edit: I think I know the answer, [x] is the same as |x| Right?

4. Originally Posted by Jarod_C
thanks for the fast reply, how about [x]? I guess I should ask now instead of when it comes up in the future.
You don't get square brackets unless you want to show a bracket of a bracket in which case a square bracket looks neater so...

e.g. $\displaystyle [ (x + 2) (x - 2)] - 2$
(In which case you are saying, find the value of the brackets first then do the arithmetic outside the square bracket).

A square bracket doesn't change the value of the number so it is the same as $\displaystyle (x)$ curvy bracket.

EDIT: It is not the same as modulus = $\displaystyle |x|$

5. I've got a test tomarrow, and the quickness of your replys are helping a lot.
Thanks for the quick help, thanks to air for supporting the site, and thanks to the owners of the site.