If x^2 + y^2 = 29 , what is the value of (x - y)^2 ?
1] xy = 10
2] x = 5
I was confused with the given OA , but actually while typing this question i realised my fault and understood why OA is so .OA after some discussions.
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Finding values .... !!!
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Anurag@Gurome
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(x - y)² = (x² + 2xy + y²) = (x² + y²) + 2xy = 29 + 2xyAIM GMAT wrote:If x² + y² = 29 , what is the value of (x - y)² ?
1] xy = 10
2] x = 5
If we know the value of xy, we can determine the value of (x - y)².
Statement 1: Sufficient
Statement 2: x = 5
Implies, x² = 25
Hence, y² = (29 - 25) = 4 => y = ±2
Hence, xy = ±10 => 2xy = ±20
Not sufficient
The correct answer is A.
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gmatmachoman
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(x - y)^2 = x^2 +Y^2 -2XYAIM GMAT wrote:If x^2 + y^2 = 29 , what is the value of (x - y)^2 ?
1] xy = 10
2] x = 5
I was confused with the given OA , but actually while typing this question i realised my fault and understood why OA is so .OA after some discussions.
st 1:
use the given value & substitute that.... Sufficient
St 2:
Using this u can't get "distinct" value of Yas Y can be postive or negative
Pick A
