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

It is currently 26 Aug 2016, 05:32
GMAT Club Tests

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

y = x^2 + 6x 7, x= 1). x is positive integer 2). y^2=y

  post reply Question banks Downloads My Bookmarks Reviews Important topics  
Author Message
Manager
Manager
avatar
Joined: 03 Jul 2006
Posts: 176
Followers: 1

Kudos [?]: 19 [0], given: 0

y = x^2 + 6x 7, x= 1). x is positive integer 2). y^2=y [#permalink]

Show Tags

New post 12 Sep 2006, 19:50
00:00
A
B
C
D
E

Difficulty:

(N/A)

Question Stats:

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

HideShow timer Statistics

This topic is locked. If you want to discuss this question please re-post it in the respective forum.

y = x^2 + 6x – 7, x=

1). x is positive integer

2). y^2=y
Manager
Manager
avatar
Joined: 03 Jul 2006
Posts: 176
Followers: 1

Kudos [?]: 19 [0], given: 0

 [#permalink]

Show Tags

New post 12 Sep 2006, 20:11
why not 'A'

from the stem, x = -7 or 1

and A says x has to be +ve then x must be 1 ?
VP
VP
avatar
Joined: 28 Mar 2006
Posts: 1381
Followers: 2

Kudos [?]: 28 [0], given: 0

 [#permalink]

Show Tags

New post 12 Sep 2006, 20:14
rkatl wrote:
why not 'A'

from the stem, x = -7 or 1

and A says x has to be +ve then x must be 1 ?


here the eq is not =0 but equal to y.

How can you deduce anything from 1 only?

either it has to be C or E
CEO
CEO
User avatar
Joined: 20 Nov 2005
Posts: 2911
Schools: Completed at SAID BUSINESS SCHOOL, OXFORD - Class of 2008
Followers: 22

Kudos [?]: 233 [0], given: 0

 [#permalink]

Show Tags

New post 12 Sep 2006, 21:25
C

St1: clearly INSUFF

St2: y = 0 or y = 1.
then there are two equations
x^2 + 6x-7 = 0 gives us x = 1 or -7 and
x^2+6x-8 = 0 gives us two non-integer roots.: INSUFF

Together:
x = 1.: SUFF
_________________

SAID BUSINESS SCHOOL, OXFORD - MBA CLASS OF 2008

SVP
SVP
User avatar
Joined: 05 Jul 2006
Posts: 1512
Followers: 5

Kudos [?]: 241 [0], given: 39

GMAT ToolKit User
 [#permalink]

Show Tags

New post 13 Sep 2006, 00:27
the key here is statment b

y^2 =y thus y is either = {-1,1,0}....insuff

both together

x is positive and y = x^2 + 6x – 7

if y = -1 thus x^2 + 6x-6 = 0....this equation has two non intiger answers one +ve and one -ve ( test with (b^2 - 4ac)....insuff

y = 1 thus x^2 + 6x-8 = 0 this equation has non intiger answers one +ve and one -ve....insuff

if y = 0 the equation has two intiger roots and as it is mentioned in one that x is positive intiger

thus C is my answer
  [#permalink] 13 Sep 2006, 00:27
Display posts from previous: Sort by

y = x^2 + 6x 7, x= 1). x is positive integer 2). y^2=y

  post reply Question banks Downloads My Bookmarks Reviews Important topics  


GMAT Club MBA Forum Home| About| 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®.