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

It is currently 19 Aug 2014, 23:25

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

What is the value of x? (1) root(x^4)= 9 (2) root(x^2)= -x

  Question banks Downloads My Bookmarks Reviews Important topics  
Author Message
TAGS:
Director
Director
User avatar
Joined: 25 Oct 2008
Posts: 611
Location: Kolkata,India
Followers: 8

Kudos [?]: 158 [0], given: 100

GMAT Tests User
What is the value of x? (1) root(x^4)= 9 (2) root(x^2)= -x [#permalink] New post 27 Sep 2009, 21:33
00:00
A
B
C
D
E

Difficulty:

(N/A)

Question Stats:

100% (02:05) correct 0% (00:00) wrong based on 2 sessions
What is the value of x?

(1) root(x^4)= 9

(2) root(x^2)= -x

How is the ans
[Reveal] Spoiler:
C


1:we get two values.Insuff.B C E
2: x= -x.This is only poss. when x=0.Suff. IMO:B

What am i missing?
_________________

countdown-beginshas-ended-85483-40.html#p649902

Manager
Manager
avatar
Joined: 11 Sep 2009
Posts: 129
Followers: 4

Kudos [?]: 168 [0], given: 6

GMAT Tests User
Re: value of x? [#permalink] New post 27 Sep 2009, 22:50
Statement 1: Root(x^4) = 9

x= 3 or x = -3

Statement 1 is insufficent.

Statement 2: root(x^2)= -x

x <= 0 (Think about it: if X = -3, x^2 = 9. The root of 9 is 3. -x = -(-3) = 3.)

Statements Analyzed Together

One value: -3

Therefore answer is C .

Last edited by AKProdigy87 on 27 Sep 2009, 23:37, edited 2 times in total.
Senior Manager
Senior Manager
avatar
Joined: 08 Jan 2009
Posts: 332
Followers: 2

Kudos [?]: 66 [0], given: 5

GMAT Tests User
Re: value of x? [#permalink] New post 27 Sep 2009, 23:15
Will go with C.

stmt 2 :

root(x^2)= -x can be written as |x| + x = 0 so solution for this is x<=0

stmt 1 :

same ways can be written as | x^2 | = 9

so x can be + 3 or -3

combining :

yes X = -3 so Ans is C.
Director
Director
User avatar
Joined: 25 Oct 2008
Posts: 611
Location: Kolkata,India
Followers: 8

Kudos [?]: 158 [0], given: 100

GMAT Tests User
Re: value of x? [#permalink] New post 28 Sep 2009, 01:51
I am sorry its still not clear:
Stmt 2:
Root(x^2)=-x
x=-x
2x=0
x=0 Hence B :oops:
_________________

countdown-beginshas-ended-85483-40.html#p649902

1 KUDOS received
Tuck Thread Master
User avatar
Joined: 20 Aug 2009
Posts: 312
Location: Tbilisi, Georgia
Schools: Stanford (in), Tuck (WL), Wharton (ding), Cornell (in)
Followers: 12

Kudos [?]: 88 [1] , given: 69

GMAT Tests User
Re: value of x? [#permalink] New post 28 Sep 2009, 03:52
1
This post received
KUDOS
tejal777 wrote:
I am sorry its still not clear:
Stmt 2:
Root(x^2)=-x
x=-x
2x=0
x=0 Hence B :oops:



general rule is that

\sqrt{x^2}=|x|

|x| = x, if x>=0

|x| = -x, if x<0

http://en.wikipedia.org/wiki/Square_root


so from the Statement 2 it becomes clear, that x is negative
Senior Manager
Senior Manager
avatar
Joined: 31 Aug 2009
Posts: 422
Location: Sydney, Australia
Followers: 6

Kudos [?]: 106 [0], given: 20

GMAT Tests User
Re: value of x? [#permalink] New post 28 Sep 2009, 04:04
Thanks for the info and link Shalva.
Re: value of x?   [#permalink] 28 Sep 2009, 04:04
    Similar topics Author Replies Last post
Similar
Topics:
6 Experts publish their posts in the topic What is root(x^2•y^2) if x < 0 and y > 0? registerincog 4 21 Nov 2013, 00:51
12 Experts publish their posts in the topic If x#0, then root(x^2)/x= Fremontian 17 14 Dec 2009, 16:58
What is the value of x? sq root(x^4)=9 sq root(x^2)=-x tejal777 7 06 Nov 2009, 05:32
What is the value of x? (1) sq. root of x^4 = 9 (2) the cpcalanoc 1 19 Dec 2004, 18:22
What is the value of the integer X? (1) X^2 = 9. (2) X is a saurya_s 2 17 Sep 2004, 11:27
Display posts from previous: Sort by

What is the value of x? (1) root(x^4)= 9 (2) root(x^2)= -x

  Question banks Downloads My Bookmarks Reviews Important topics  


cron

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®.