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# 4x^2 + 4y^2

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Joined: 18 Apr 2015
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Kudos [?]: 1030 [0], given: 4640

4x^2 + 4y^2 [#permalink]  09 May 2018, 10:03
Expert's post
00:00

Question Stats:

90% (00:53) correct 10% (00:14) wrong based on 10 sessions
 Quantity A Quantity B $$4x^2 + 4y^2$$ $$( 2x + 2y)^2$$

A)The quantity in Column A is greater.
B)The quantity in Column B is greater.
C)The two quantities are equal.
D)The relationship cannot be determined from the information given.
[Reveal] Spoiler: OA

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GRE Instructor
Joined: 10 Apr 2015
Posts: 1232
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Kudos [?]: 1115 [1] , given: 7

Re: 4x^2 + 4y^2 [#permalink]  09 May 2018, 12:56
1
KUDOS
Expert's post
Carcass wrote:
 Quantity A Quantity B $$4x^2 + 4y^2$$ $$(2x + 2y)^2$$

A)The quantity in Column A is greater.
B)The quantity in Column B is greater.
C)The two quantities are equal.
D)The relationship cannot be determined from the information given.

Given:
Quantity A: 4x² + 4y²
Quantity B: (2x + 2y)²

Expand and simplify Quantity B:
Quantity A: 4x² + 4y²
Quantity B: 4x² + 8xy + 4y²

Subtract 4x² from both quantities:
Quantity A: 4y²
Quantity B: 8xy + 4y²

Subtract 4y² from both quantities:
Quantity A: 0
Quantity B: 8xy

At this point, we can see that the correct answer is D
If x = 0 and y = 0, then the two quantities are equal
If x = 1 and y = 1, then Quantity B is greater

Cheers,
Brent
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Brent Hanneson – Creator of greenlighttestprep.com

Re: 4x^2 + 4y^2   [#permalink] 09 May 2018, 12:56
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