Properties of Number : Problem

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Properties of Number : Problem

by BlindVision » Sat Mar 07, 2009 4:26 pm
If xy IS NOT equal to 0, is x/y < 0?

1) x = -y
2) -x = -(-y)

OA = D

Can someone please explain? For Statement 1 I divided by -y and the Statement 2 I divided by +y but I know that I'm not doing it correctly. Thanks!
Source: — Data Sufficiency |

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by Feep » Sat Mar 07, 2009 9:58 pm
First off, the two statements given are EXACTLY the same. -x = -(-y) is the same as is -x = y is the same is x = -y. So right off the bat, the answer can only be D or E.

The question merely asks if this fraction is negative, which is the same as asking if x and y have the same sign (positive) or differing signs (negative). Both statements clearly indicate the two numbers have different signs, and so the answer is D.
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by BlindVision » Sat Mar 07, 2009 10:19 pm
You made it so easy to understand. Thanks!