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Value of X - A DS problem.

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Source: — Data Sufficiency |
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by ajith » Wed Feb 24, 2010 10:34 pm
mah927 wrote:What is the value of x ?
(1) x^2 + y^2 = 25
(2) xy = 12

OA is E. I thought it is C. Since you have two equations. Am I totally missing something? Thanks in advance for help.
x^2 + y^2 = 25
xy = 12

x^2+y^2 +2xy = 49

(x+y)^2 = 49


x^2+y^2 -2xy = 1

(x-y)^2 = 1

x= -3 y = -4 and x =4 y = 3 both satisfy this, no unique value for x hence E
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