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555-605 (Medium)|   Algebra|      
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Bunuel
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What is the value of x ? (1) x^2 - y^2 = 27 (2) x = 2y 01 Jan 2021, 08:15
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Difficulty:

35% (medium)

Question Stats:

65% (01:03) correct 35% (01:07) wrong based on 68 sessions

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What is the value of x ?

(1) x^2 - y^2 = 27
(2) x = 2y
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chetan2u
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What is the value of x ? (1) x^2 - y^2 = 27 (2) x = 2y 01 Jan 2021, 21:05
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Bunuel
What is the value of x ?

(1) x^2 - y^2 = 27
(2) x = 2y
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Clearly individual statements have two variables each, so taken alone cannot give the value of x.

Combined
x=2y
\(x^2-y^2=27........(2y)^2-y^2=27........3y^2=27........y^2=9\)
So \(x^2-9=27........x^2=36\)
x can be 6 or -6.
Insufficient

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