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# Is x = y? (1) x^2 = xy (2) x^2 = y^2

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Manager
Joined: 10 Dec 2011
Posts: 89
Location: India
Concentration: Finance, Economics
GMAT Date: 09-28-2012
WE: Accounting (Manufacturing)
Is x = y? (1) x^2 = xy (2) x^2 = y^2  [#permalink]

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Updated on: 17 Nov 2017, 08:00
4
00:00

Difficulty:

65% (hard)

Question Stats:

42% (01:16) correct 58% (00:57) wrong based on 52 sessions

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Is x = y?

(1) x^2 = xy
(2) x^2 = y^2

Originally posted by talismaaniac on 17 Nov 2017, 07:49.
Last edited by Bunuel on 17 Nov 2017, 08:00, edited 2 times in total.
Renamed the topic and edited the question.
Senior Manager
Joined: 06 Jul 2016
Posts: 382
Location: Singapore
Concentration: Strategy, Finance
Re: Is x = y? (1) x^2 = xy (2) x^2 = y^2  [#permalink]

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17 Nov 2017, 08:03
talismaaniac wrote:
Is x = y?

(1) x^2 = xy

$$x^2$$ - xy = 0
=> x (x-y) = 0
=> x = 0, y

Insufficient.

Quote:
(2) x^2 = y^2

$$x^2$$ - $$y^2$$ = 0
=> x = y,-y

Insufficient.

Quote:
Combining Both the Statements

x = 0,y
x = -y,y

=> x = y

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Joined: 02 Sep 2009
Posts: 50000
Re: Is x = y? (1) x^2 = xy (2) x^2 = y^2  [#permalink]

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17 Nov 2017, 08:04
Is x = y?

(1) x^2 = xy
x^2 - xy = 0
x(x - y) = 0
x = 0 or x = y. Not sufficient.

(2) x^2 = y^2
Take the square root: |x| = |y|.
x = y or x = -y. Not sufficient.

(1)+(2) If from (1) we have the first case x = 0, then from (2) x = y = 0, so we'll have and YES answer and if from (1) we'll have the second case, x = y, we'll still have an YES answer. Sufficient.

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Re: Is x = y? (1) x^2 = xy (2) x^2 = y^2 &nbs [#permalink] 17 Nov 2017, 08:04
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