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Algebra

by [email protected] » Tue Nov 12, 2013 6:53 am
While I understand the explanation why aren't in this solution we considering the possibility of the values of x and y to be fractions?

In that case wont the answer differ?
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by Uva@90 » Tue Nov 12, 2013 7:43 am
[email protected] wrote:While I understand the explanation why aren't in this solution we considering the possibility of the values of x and y to be fractions?

In that case wont the answer differ?
Shibsriz,
Thanks for posting the NICE Question.

I could not understand, what makes you to think FRACTION affect the SIGN of number.
Fraction does not affect the sign.
For example,
SQRT(25) =5 :: SQRT(125/5) = 5
Cube-root(-64) = -4 :: Cube-root(-128/2) = -4

If you post thoughts in much clearer way it could help all.

Thanks in advance.

Regards,
Uva.
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by [email protected] » Tue Nov 12, 2013 2:20 pm
Hi shibsriz,

This question revolves around the inequality "<". Whether the number are fractions or integers is irrelevant; the relevant issue is whether they're POSITIVE or NEGATIVE.

Since we're not allowed to use 0, we can deduce a number of things about the "pieces" of the equation (both in the question and in the two Facts):

1) (X)^-4 = 1/(X^4) this calculation will ALWAYS be POSITIVE

2) (Z)^-2 = 1/(X^2) this calculation will ALWAYS be POSITIVE

So the real question is: Is the "cube root of Y" positive or negative?

Both Facts point out that Y will be greater than a positive value, which is why they're both Sufficient on their own.

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