value of expression

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value of expression

by shahab03 » Mon Aug 31, 2009 10:14 am
answer is E. but why is it not C.
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by larrybird » Mon Aug 31, 2009 2:18 pm
This is a common trap. GMAT wants you to just cancel the squared root with the power of two. But think about it: the stem only says that x cannot be zero. What happens if x is negative, for instance x=-1? Is the final correct answer c. 1 as you mention ??? No! the answer would be -1.
Answer E is correct.