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What is the value of x

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Source: — Data Sufficiency |
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by sam2304 » Sat Apr 14, 2012 7:07 pm
Both are same.

1. 2x + 1 = 0, x = -1/2 SUFF
2. (x+1)^2 = x^2 = x^2 + 2x + 1 = x^2 => 2x + 1 = 0. SUFF

IMO D.
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by killer1387 » Sun Apr 15, 2012 3:50 am
PGMAT wrote:What is the value of x ?
(1) 2x + 1 = 0
(2) (x+1)^2 = x^2

OA D

Can some one explain how statement 2 is sufficient?

Thanks.
1) SUFFICIENT
2) (X+1-X)(X+1+X)=0=> X=UNIQUE VALUE
SUFFICIENT
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by Anurag@Gurome » Sun Apr 15, 2012 7:35 pm
PGMAT wrote:What is the value of x ?
(1) 2x + 1 = 0
(2) (x+1)^2 = x^2

OA D

Can some one explain how statement 2 is sufficient?

Thanks.
(1) 2x + 1 = 0 implies x = -1/2; SUFFICIENT.

(2) (x + 1)² = x²
Applying the identity, (a + b)² = a² + 2ab + b²
x² + 2x + 1 = x²
2x + 1 = 0
x = 1/2; SUFFICIENT.

The correct answer is D.
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