GMAT Question of the Day - Daily to your Mailbox; hard ones only

 It is currently 20 Aug 2018, 21:08

### GMAT Club Daily Prep

#### Thank you for using the timer - this advanced tool can estimate your performance and suggest more practice questions. We have subscribed you to Daily Prep Questions via email.

Customized
for You

we will pick new questions that match your level based on your Timer History

Track

every week, we’ll send you an estimated GMAT score based on your performance

Practice
Pays

we will pick new questions that match your level based on your Timer History

# PS: I found it tough

Author Message
Current Student
Joined: 28 Dec 2004
Posts: 3280
Location: New York City
Schools: Wharton'11 HBS'12
PS: I found it tough  [#permalink]

### Show Tags

03 Feb 2009, 17:23
00:00

Difficulty:

(N/A)

Question Stats:

0% (00:00) correct 0% (00:00) wrong based on 1 sessions

### HideShow timer Statistics

From MGMAT..they say this is a 600 level question..i beg to disagree..

If (16x^4 – 81y^4)/ (2x + 3y) = 12x^2 + 27y^2 and 4x + 3y = 9, what is x?

--== Message from GMAT Club Team ==--

This is not a quality discussion. It has been retired.

If you would like to discuss this question please re-post it in the respective forum. Thank you!

To review the GMAT Club's Forums Posting Guidelines, please follow these links: Quantitative | Verbal Please note - we may remove posts that do not follow our posting guidelines. Thank you.
SVP
Joined: 29 Aug 2007
Posts: 2419
Re: PS: I found it tough  [#permalink]

### Show Tags

03 Feb 2009, 19:11
FN wrote:
From MGMAT..they say this is a 600 level question..i beg to disagree..

If (16x^4 – 81y^4)/ (2x + 3y) = 12x^2 + 27y^2 and 4x + 3y = 9, what is x?

(16x^4 – 81y^4)/(2x + 3y) = 12x^2 + 27y^2
[(2x + 3y)(2x - 3y)(4x^2 + 9y^2)]/(2x + 3y) = 3 (4x^2 + 9y^2)
2x - 3y = 3 ...................................1
4x + 3y = 9 ...................................2

add 1 and 2: 6x = 12 or x = 2

agree that its 600 level question
_________________

Gmat: http://gmatclub.com/forum/everything-you-need-to-prepare-for-the-gmat-revised-77983.html

GT

Current Student
Joined: 28 Dec 2004
Posts: 3280
Location: New York City
Schools: Wharton'11 HBS'12
Re: PS: I found it tough  [#permalink]

### Show Tags

03 Feb 2009, 19:50
this is at least 680 level.. recognizing x^2 - y^2 form requires greater skills

GMAT TIGER wrote:
FN wrote:
From MGMAT..they say this is a 600 level question..i beg to disagree..

If (16x^4 – 81y^4)/ (2x + 3y) = 12x^2 + 27y^2 and 4x + 3y = 9, what is x?

(16x^4 – 81y^4)/(2x + 3y) = 12x^2 + 27y^2
[(2x + 3y)(2x - 3y)(4x^2 + 9y^2)]/(2x + 3y) = 3 (4x^2 + 9y^2)
2x - 3y = 3 ...................................1
4x + 3y = 9 ...................................2

add 1 and 2: 6x = 12 or x = 6

agree that its 600 level question
Intern
Joined: 06 Oct 2006
Posts: 14
Re: PS: I found it tough  [#permalink]

### Show Tags

04 Feb 2009, 01:36
GMAT TIGER wrote:
FN wrote:
From MGMAT..they say this is a 600 level question..i beg to disagree..

If (16x^4 – 81y^4)/ (2x + 3y) = 12x^2 + 27y^2 and 4x + 3y = 9, what is x?

(16x^4 – 81y^4)/(2x + 3y) = 12x^2 + 27y^2
[(2x + 3y)(2x - 3y)(4x^2 + 9y^2)]/(2x + 3y) = 3 (4x^2 + 9y^2)
2x - 3y = 3 ...................................1
4x + 3y = 9 ...................................2

add 1 and 2: 6x = 12 or x = 6

agree that its 600 level question

Minor mistake in calculation though:
6x = 12 means x = 2 (not 6) .. not very imp
VP
Joined: 18 May 2008
Posts: 1176
Re: PS: I found it tough  [#permalink]

### Show Tags

04 Feb 2009, 03:55
Yes, I solved in exactly the same way as GMATTIGER (feeling a bit lazy in writing all those equations again
I will categorize it in 600+ range
Current Student
Joined: 28 Dec 2004
Posts: 3280
Location: New York City
Schools: Wharton'11 HBS'12
Re: PS: I found it tough  [#permalink]

### Show Tags

04 Feb 2009, 08:31
wow its unanimous.. somehow i felt this question was tough i spent over 4 min on it..

i guess i found one of my problem spots..i.e realizing the a^2 - b^2 form...

anyone have any questions similiar to this one that i can practice on?

SVP
Joined: 29 Aug 2007
Posts: 2419
Re: PS: I found it tough  [#permalink]

### Show Tags

04 Feb 2009, 09:13
D-dude wrote:
GMAT TIGER wrote:
FN wrote:
From MGMAT..they say this is a 600 level question..i beg to disagree..

If (16x^4 – 81y^4)/ (2x + 3y) = 12x^2 + 27y^2 and 4x + 3y = 9, what is x?

(16x^4 – 81y^4)/(2x + 3y) = 12x^2 + 27y^2
[(2x + 3y)(2x - 3y)(4x^2 + 9y^2)]/(2x + 3y) = 3 (4x^2 + 9y^2)
2x - 3y = 3 ...................................1
4x + 3y = 9 ...................................2

add 1 and 2: 6x = 12 or x = 6

agree that its 600 level question

Minor mistake in calculation though:
6x = 12 means x = 2 (not 6) .. not very imp

Thanks for the correction.
I edited the error..

--== Message from GMAT Club Team ==--

This is not a quality discussion. It has been retired.

If you would like to discuss this question please re-post it in the respective forum. Thank you!

To review the GMAT Club's Forums Posting Guidelines, please follow these links: Quantitative | Verbal Please note - we may remove posts that do not follow our posting guidelines. Thank you.

_________________

Gmat: http://gmatclub.com/forum/everything-you-need-to-prepare-for-the-gmat-revised-77983.html

GT

Re: PS: I found it tough &nbs [#permalink] 04 Feb 2009, 09:13
Display posts from previous: Sort by

# Events & Promotions

 Powered by phpBB © phpBB Group | Emoji artwork provided by EmojiOne Kindly note that the GMAT® test is a registered trademark of the Graduate Management Admission Council®, and this site has neither been reviewed nor endorsed by GMAC®.