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GMATPrep question - absolute value

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by rainbownlife » Tue Mar 04, 2008 9:34 am
anybody?
I am looking for approach to solve such problems with roots and equations/inequalities.
thanks in advance!
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by rainbownlife » Tue Mar 04, 2008 10:01 am
Its okay, ignore it...

I got it ! :)
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by anshul265 » Tue Mar 04, 2008 5:00 pm
square root of a^2 = a or -a

similarly square root of (x-3)^2 = x-3 or -(x-3) [or 3-x]. Thus this eqn will not hold true for any value of x.

Hence the answer is E.

-AN[/list]
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by soumitb » Tue Mar 11, 2008 7:12 pm
sq.root of (x-3)^2 = sq.root of (x-3)(x-3) = (x-3)

So, we can rephrase the question as :

Is (x-3) = (3-x)
=> 2x = 6
or Is x=3?

Statement 1: x not equal to 3.
Therefore Stmt. 1 is sufficient

Statement 2: -x|x|>0.
This does not tell whether x=3.

Therefore answer is A.
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