It is currently 23 Sep 2017, 14:53

### 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

# Events & Promotions

###### Events & Promotions in June
Open Detailed Calendar

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

Author Message
Manager
Joined: 03 Jul 2006
Posts: 175

Kudos [?]: 30 [0], given: 0

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

### Show Tags

12 Sep 2006, 19:50
00:00

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

Kudos [?]: 30 [0], given: 0

Manager
Joined: 03 Jul 2006
Posts: 175

Kudos [?]: 30 [0], given: 0

### Show Tags

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 ?

Kudos [?]: 30 [0], given: 0

VP
Joined: 28 Mar 2006
Posts: 1367

Kudos [?]: 38 [0], given: 0

### Show Tags

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

Kudos [?]: 38 [0], given: 0

CEO
Joined: 20 Nov 2005
Posts: 2893

Kudos [?]: 316 [0], given: 0

Schools: Completed at SAID BUSINESS SCHOOL, OXFORD - Class of 2008

### Show Tags

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

Kudos [?]: 316 [0], given: 0

SVP
Joined: 05 Jul 2006
Posts: 1742

Kudos [?]: 418 [0], given: 49

### Show Tags

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 â€“ 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

Kudos [?]: 418 [0], given: 49

13 Sep 2006, 00:27
Display posts from previous: Sort by