Find all School-related info fast with the new School-Specific MBA Forum

It is currently 22 Sep 2014, 22:44

Close

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
Your Progress

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

Not interested in getting valuable practice questions and articles delivered to your email? No problem, unsubscribe here.

Events & Promotions

Events & Promotions in June
Open Detailed Calendar

If x and y are positive, what is the value of x y? (1) (x^2

  Question banks Downloads My Bookmarks Reviews Important topics  
Author Message
TAGS:
1 KUDOS received
Manager
Manager
User avatar
Joined: 27 Mar 2008
Posts: 99
Followers: 1

Kudos [?]: 10 [1] , given: 0

If x and y are positive, what is the value of x y? (1) (x^2 [#permalink] New post 10 Jun 2008, 12:33
1
This post received
KUDOS
00:00
A
B
C
D
E

Difficulty:

(N/A)

Question Stats:

0% (00:00) correct 0% (00:00) wrong based on 0 sessions
If x and y are positive, what is the value of x – y?
(1) (x^2 – y^2) / (x + y) = 4
(2) x + y = 7
_________________

MBA Blog: University of Minnesota Carlson School of Management- http://unconventionalapplicant.blogspot.com/

2 KUDOS received
SVP
SVP
User avatar
Joined: 30 Apr 2008
Posts: 1893
Location: Oklahoma City
Schools: Hard Knocks
Followers: 30

Kudos [?]: 435 [2] , given: 32

GMAT Tests User
Re: DS algebra [#permalink] New post 10 Jun 2008, 12:43
2
This post received
KUDOS
A

Statement #1

If you have
\frac{(x^2-y^2)}{(x+y)} = 4 this the same as

\frac{(x+y)(x-y)}{(x+y)} = 4 The (x+y) on the top and bottom cancel out leaving only:

(x-y)=4

Statement #2

x + y = 7, then x = 7 - y. No matter what we do, I don't think it's possible to get a number value for x-y from x+y=7.

We could try to add x to both sides of x = 7 -y to get 2x = 7 + x - y, then 2x - 7 = x-y, but this still is not an actual value.

carlson2010 wrote:
If x and y are positive, what is the value of x – y?
(1) (x^2 – y^2) / (x + y) = 4
(2) x + y = 7

_________________

------------------------------------
J Allen Morris
**I'm pretty sure I'm right, but then again, I'm just a guy with his head up his a$$.

Get the best GMAT Prep Resources with GMAT Club Premium Membership


Last edited by jallenmorris on 10 Jun 2008, 12:48, edited 3 times in total.
Manager
Manager
User avatar
Joined: 27 Mar 2008
Posts: 99
Followers: 1

Kudos [?]: 10 [0], given: 0

Re: DS algebra [#permalink] New post 10 Jun 2008, 12:44
jallenmorris wrote:
A

carlson2010 wrote:
If x and y are positive, what is the value of x – y?
(1) (x^2 – y^2) / (x + y) = 4
(2) x + y = 7


You are right. Can you show how? Thanks.
_________________

MBA Blog: University of Minnesota Carlson School of Management- http://unconventionalapplicant.blogspot.com/

1 KUDOS received
Intern
Intern
avatar
Joined: 10 Jun 2008
Posts: 7
Followers: 0

Kudos [?]: 4 [1] , given: 0

Re: DS algebra [#permalink] New post 10 Jun 2008, 12:45
1
This post received
KUDOS
(1) (x^2 – y^2) / (x + y) = 4
(2) x + y = 7

From statement 1:
(x^2 – y^2) / (x + y) = 4
=>
(x + y) * (x - y) / (x + y) = 4
=>
x - y = 4; SUFFICIENT

Statement 2 is insufficient
counter-example: (x, y) = {(6, 1), (5, 2), ...}
Re: DS algebra   [#permalink] 10 Jun 2008, 12:45
    Similar topics Author Replies Last post
Similar
Topics:
7 Experts publish their posts in the topic If y= (x-1)(x+2), then what is the least possible value of y fozzzy 4 07 Jul 2013, 06:39
1 Experts publish their posts in the topic If x + 2y + 1 = y - x, what is the value of x? fiendex 4 06 Feb 2012, 07:33
1 If x and y are positive, what is the value of x-y? 1) (X^2 - hardaway7 3 29 Dec 2008, 10:26
What is the value of X^2 -Y^2? 1. x+y=2x 2. x+y=0 I jamesrwrightiii 4 17 Jul 2006, 20:59
What is the value of x^2 + 2xy + y^2? 1) x + y = 7 2) x = 2 john2005 6 18 Apr 2006, 18:13
Display posts from previous: Sort by

If x and y are positive, what is the value of x y? (1) (x^2

  Question banks Downloads My Bookmarks Reviews Important topics  


GMAT Club MBA Forum Home| About| Privacy Policy| Terms and Conditions| GMAT Club Rules| Contact| Sitemap

Powered by phpBB © phpBB Group and phpBB SEO

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®.