DS can someone explain

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DS can someone explain

by radhika1306 » Thu Aug 30, 2007 11:48 am
If x(x - 5)(x + 2) = 0, is x negative?
(1) x2 – 7x ≠ 0
(2) x2 –2x –15 ≠ 0

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by kajcha » Thu Aug 30, 2007 12:01 pm
From the question x = 0 or 5 or -2

Stmt 1 - x(x-7) <> 0 means x neq 0 and x neq 7 NOT SUFF

Stmt 2 - (x+3)(x-5) neq 0 means x neq -3 and x neq 5 NOT SUFF

Together x neq 0, x neq 5 so x = -2 to hold the question true. SUFF

Ans C

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Re: DS can someone explain

by ratindasgupta » Thu Aug 30, 2007 12:06 pm
radhika1306 wrote:If x(x - 5)(x + 2) = 0, is x negative?
(1) x2 – 7x &#8800; 0
(2) x2 –2x –15 &#8800; 0
First of all, i'm assuming that x2 means x^2.

For x(x - 5)(x + 2) = 0, x has to be 0, 5 or -2.

1) It states that x &#8800; 0 and x &#8800; 7. So x could be 5 or -2. So INSUFF

2) It states that x &#8800; 5 and x &#8800; -3. So x could be 0 or -2. So INSUFF

Combining 1 & 2, we get that x &#8800; 0 and 5. Then x must be -2. So x is negative. Answer is therefore C.

What's the OA?

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by radhika1306 » Thu Aug 30, 2007 12:54 pm
thanks