GMAT Prep - Number Properties

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by reachac » Mon Jul 14, 2008 8:22 pm
IMO E

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by kishore » Mon Jul 14, 2008 8:25 pm
Answer) E = |X|/X


If X not equal to Zero, sqrt(X^2)/ X

If X = -1

sqrt(X^2)/ X = sqrt ( -1 ^ 2)/ -1 = sqrt(1)/-1 = 1/-1 = -1

If X = 1

sqrt(X^2)/ X = sqrt ( 1 ^ 2)/ 1 = sqrt(1)/1 = 1/1 = 1


So, X can be -1 or + 1

look at the answers

if x = -1
=> |x|/x = |-1|/-1 = 1/-1 = -1

if x = 1
=> |x|/x = |1|/1 = 1/1 = 1

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by sudhir3127 » Mon Jul 14, 2008 9:26 pm
My answer is E.

sq root x^2 = +- X

the only answer choice which satisfies this is E.

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by raunekk » Tue Jul 15, 2008 4:39 am
E.. same explanation.