It is currently 15 Nov 2018, 06:20
My 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.

4 - x^2

  Question banks Downloads My Bookmarks Reviews Important topics  
Author Message
TAGS:
1 KUDOS received
Moderator
Moderator
User avatar
Joined: 18 Apr 2015
Posts: 4876
Followers: 74

Kudos [?]: 973 [1] , given: 4479

CAT Tests
4 - x^2 [#permalink] New post 23 Jan 2018, 14:46
1
This post received
KUDOS
Expert's post
00:00

Question Stats:

71% (00:32) correct 28% (00:26) wrong based on 28 sessions



Quantity A
Quantity B
\(4 - x^2\)
\(5\)


A) Quantity A is greater.
B) Quantity B is greater.
C) The two quantities are equal.
D) The relationship cannot be determined from the information given.

Kudos for right answer and explanation
[Reveal] Spoiler: OA

_________________

Get the 2 FREE GREPrepclub Tests

1 KUDOS received
Manager
Manager
Joined: 02 Jan 2018
Posts: 66
Followers: 0

Kudos [?]: 30 [1] , given: 0

Re: 4 - x^2 [#permalink] New post 24 Jan 2018, 02:48
1
This post received
KUDOS
Quantity B is greater. As x=+2 or -2, which are anyways smaller than 5
1 KUDOS received
Intern
Intern
Joined: 18 May 2016
Posts: 35
Followers: 0

Kudos [?]: 15 [1] , given: 13

Re: 4 - x^2 [#permalink] New post 25 Jan 2018, 01:48
1
This post received
KUDOS
Note that x² will always be a positive number (or 0) and thus in the equation 4 - x² always subtracted from four.
As 4 < 5, there is no number that can be subtracted from 4 to yield a number equal to or bigger than 5.
Correct answer is B.
Intern
Intern
Joined: 24 Jan 2018
Posts: 31
Followers: 0

Kudos [?]: 4 [0], given: 8

Re: 4 - x^2 [#permalink] New post 26 Jan 2018, 11:59
B
Intern
Intern
Joined: 17 Feb 2018
Posts: 31
Followers: 0

Kudos [?]: 24 [0], given: 2

Re: 4 - x^2 [#permalink] New post 24 Feb 2018, 10:43
if x=i i^2=-1 4-(-1)=5
why the answer isn't D
Moderator
Moderator
User avatar
Joined: 18 Apr 2015
Posts: 4876
Followers: 74

Kudos [?]: 973 [0], given: 4479

CAT Tests
Re: 4 - x^2 [#permalink] New post 24 Feb 2018, 11:55
Expert's post
It is impossible.

\(x^2 - 4 = (x-2)(x+2)\).

The roots are ONLY \(x=2\) and \(x=-2\)

B is always bigger than A.

Hope this helps.

regards
_________________

Get the 2 FREE GREPrepclub Tests

1 KUDOS received
GRE Instructor
User avatar
Joined: 10 Apr 2015
Posts: 1175
Followers: 44

Kudos [?]: 1048 [1] , given: 6

CAT Tests
Re: 4 - x^2 [#permalink] New post 24 Feb 2018, 13:38
1
This post received
KUDOS
Expert's post
Carcass wrote:



Quantity A
Quantity B
\(4 - x^2\)
\(5\)


A) Quantity A is greater.
B) Quantity B is greater.
C) The two quantities are equal.
D) The relationship cannot be determined from the information given.

Kudos for right answer and explanation


We can solve this question using matching operations

Given:
Quantity A: 4 - x²
Quantity B: 5

Add x² to both quantities to get:
Quantity A: 4
Quantity B: 5 + x²

Subtract 5 from both quantities to get:
Quantity A: -1
Quantity B: x²

IMPORTANT: x² is greater than or equal to zero for all values of x
So, Quantity B is definitely greater than -1

Answer: B

RELATED VIDEO FROM OUR COURSE

_________________

Brent Hanneson – Creator of greenlighttestprep.com
Image
Sign up for our free GRE Question of the Day emails

1 KUDOS received
GRE Instructor
User avatar
Joined: 10 Apr 2015
Posts: 1175
Followers: 44

Kudos [?]: 1048 [1] , given: 6

CAT Tests
Re: 4 - x^2 [#permalink] New post 24 Feb 2018, 13:40
1
This post received
KUDOS
Expert's post
hugebigmac wrote:
if x=i i^2=-1 4-(-1)=5
why the answer isn't D


ASIDE (for others wondering how i^2 = -1): i represents a complex number (aka imaginary number) such that i^2 = -1)

Good idea, hugebigmac, but all questions on the GRE are restricted to real numbers.

Cheers,
Brent
_________________

Brent Hanneson – Creator of greenlighttestprep.com
Image
Sign up for our free GRE Question of the Day emails

Intern
Intern
Joined: 24 Feb 2018
Posts: 15
Followers: 0

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

Re: 4 - x^2 [#permalink] New post 24 Feb 2018, 16:30
B
Manager
Manager
Joined: 29 Nov 2017
Posts: 190
Location: United States
GRE 1: Q142 V146
WE: Information Technology (Computer Software)
Followers: 0

Kudos [?]: 77 [0], given: 99

Re: 4 - x^2 [#permalink] New post 17 May 2018, 23:35
Carcass wrote:
It is impossible.

\(x^2 - 4 = (x-2)(x+2)\).

The roots are ONLY \(x=2\) and \(x=-2\)

B is always bigger than A.

Hope this helps.

regards



Dear Carcass, how do we know x has + and - 2 as roots. I need more clarity of topic of roots.
Manager
Manager
Joined: 29 Nov 2017
Posts: 190
Location: United States
GRE 1: Q142 V146
WE: Information Technology (Computer Software)
Followers: 0

Kudos [?]: 77 [0], given: 99

Re: 4 - x^2 [#permalink] New post 17 May 2018, 23:36
I have tried plugging in the values of x = 0,1,2,-2 and 1/5 all in all B is greater in every case..

Hence answer is B
Moderator
Moderator
User avatar
Joined: 18 Apr 2015
Posts: 4876
Followers: 74

Kudos [?]: 973 [0], given: 4479

CAT Tests
Re: 4 - x^2 [#permalink] New post 18 May 2018, 11:37
Expert's post
IshanGre wrote:
Carcass wrote:
It is impossible.

\(x^2 - 4 = (x-2)(x+2)\).

The roots are ONLY \(x=2\) and \(x=-2\)

B is always bigger than A.

Hope this helps.

regards



Dear Carcass, how do we know x has + and - 2 as roots. I need more clarity of topic of roots.




Hope this helps.

Regards
_________________

Get the 2 FREE GREPrepclub Tests

Re: 4 - x^2   [#permalink] 18 May 2018, 11:37
Display posts from previous: Sort by

4 - x^2

  Question banks Downloads My Bookmarks Reviews Important topics  


cron

GRE Prep Club Forum Home| About| Terms and Conditions and Privacy Policy| GRE Prep Club Rules| Contact

Powered by phpBB © phpBB Group

Kindly note that the GRE® test is a registered trademark of the Educational Testing Service®, and this site has neither been reviewed nor endorsed by ETS®.