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Inequality

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Source: — Data Sufficiency |
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by raviki8208 » Tue May 18, 2010 8:30 am
jainrahul1985 wrote:If x(x - 5)(x + 2) = 0, is x negative?
(1) x2 - 7x ≠ 0
(2) x2 -2x -15 ≠ 0

OA C
Given x = 0 , 5 or -2
using 1 alone, x(x-7) ≠ 0 => x ≠ 0
using 2 alone, (x-5)(x+2) ≠ 0 => x ≠ 5

using both x ≠ 0 and 5 so it be -2 SO, answer is C
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by jainrahul1985 » Tue May 18, 2010 8:49 am
Can you please explain why using 2 we can't have x not equal to 2
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by jeffedwards » Tue May 18, 2010 10:29 am
jainrahul1985 wrote:Can you please explain why using 2 we can't have x not equal to 2

Jainrahul1985, I'm not exactly sure what your question is, but I think it may be because of the small typo in statement number two in the explanation above.

X^2-2x-15 really reduces to
(x-5)(x+3)....not (x+2)

Does that answer your question?
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