Last visit was: 24 Nov 2024, 20:10 It is currently 24 Nov 2024, 20:10
Decision Tracker
My Rewards
New comers' posts
New posts
Unanswered

Close

GRE Prep 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 GRE 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.

Go to My Error Log Learn more
Close

Request Expert Reply

Confirm Cancel
PREVIOUS TOPIC
NEXT TOPIC

4 - x^2

Tags :
Find Similar Topics  About  Add a Tag

Show Tags
Hide Tags

User avatar
D
Carcass
Verbal Expert
Joined: 18 Apr 2015
Posts: 30018
Own Kudos [?]: 36379 [3]
Given Kudos: 25928
Send PM
4 - x^2 [#permalink] New post   23 Jan 2018, 14:46
2
Expert Reply
1
Bookmarks
00:00

Question Stats:

77% (00:29) correct 22% (00:25) wrong based on 135 sessions

Hide Show timer Statistics




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
ShowHide Answer
Official Answer
B
avatar
sharmaapeksha960
Manager
Manager
Joined: 02 Jan 2018
Posts: 66
Own Kudos [?]: 39 [0]
Given Kudos: 0
Send PM
Re: 4 - x^2 [#permalink] New post   24 Jan 2018, 02:48
1
Quantity B is greater. As x=+2 or -2, which are anyways smaller than 5
avatar
Matteo91
Intern
Intern
Joined: 18 May 2016
Posts: 35
Own Kudos [?]: 35 [0]
Given Kudos: 0
Send PM
Re: 4 - x^2 [#permalink] New post   25 Jan 2018, 01:48
1
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.
avatar
Linamrs
Intern
Intern
Joined: 24 Jan 2018
Posts: 31
Own Kudos [?]: 9 [0]
Given Kudos: 0
Send PM
Re: 4 - x^2 [#permalink] New post   26 Jan 2018, 11:59
B
avatar
hugebigmac
Intern
Intern
Joined: 17 Feb 2018
Posts: 31
Own Kudos [?]: 42 [2]
Given Kudos: 0
Send PM
Re: 4 - x^2 [#permalink] New post   24 Feb 2018, 10:43
2
if x=i i^2=-1 4-(-1)=5
why the answer isn't D
User avatar
D
Carcass
Verbal Expert
Joined: 18 Apr 2015
Posts: 30018
Own Kudos [?]: 36379 [2]
Given Kudos: 25928
Send PM
Re: 4 - x^2 [#permalink] New post   24 Feb 2018, 11:55
1
Expert Reply
1
Bookmarks
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
User avatar
P
GreenlightTestPrep
Retired Moderator
Joined: 10 Apr 2015
Posts: 6218
Own Kudos [?]: 12197 [0]
Given Kudos: 136
Send PM

Top Member of the Month
Re: 4 - x^2 [#permalink] New post   24 Feb 2018, 13:38
2
Carcass wrote:

This question is part of GREPrepClub - The Questions Vault Project




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
User avatar
P
GreenlightTestPrep
Retired Moderator
Joined: 10 Apr 2015
Posts: 6218
Own Kudos [?]: 12197 [0]
Given Kudos: 136
Send PM

Top Member of the Month
Re: 4 - x^2 [#permalink] New post   24 Feb 2018, 13:40
1
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
avatar
PrachiR
Intern
Intern
Joined: 24 Feb 2018
Posts: 15
Own Kudos [?]: 2 [0]
Given Kudos: 0
Send PM
Re: 4 - x^2 [#permalink] New post   24 Feb 2018, 16:30
B
avatar
IshanGre
Manager
Manager
Joined: 29 Nov 2017
Posts: 190
Own Kudos [?]: 135 [0]
Given Kudos: 0
Location: United States
GRE 1: Q142 V146
WE:Information Technology (Computer Software)
Send PM
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.
avatar
IshanGre
Manager
Manager
Joined: 29 Nov 2017
Posts: 190
Own Kudos [?]: 135 [0]
Given Kudos: 0
Location: United States
GRE 1: Q142 V146
WE:Information Technology (Computer Software)
Send PM
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
User avatar
D
Carcass
Verbal Expert
Joined: 18 Apr 2015
Posts: 30018
Own Kudos [?]: 36379 [0]
Given Kudos: 25928
Send PM
Re: 4 - x^2 [#permalink] New post   18 May 2018, 11:37
Expert Reply
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
avatar
B
Kimberly99
Manager
Manager
Joined: 10 Feb 2023
Posts: 76
Own Kudos [?]: 13 [0]
Given Kudos: 172
Send PM
Re: 4 - x^2 [#permalink] New post   14 Feb 2023, 00:26
Hi Brent GreenlightTestPrep, If I subtract 4 from both sides, I ended up A: -x^2 B: 1 . Depends on x vaule, A can be the same (if x=1) or bigger than B (if x=2). Therefore is D. Where is my understanding going wrong here? Thanks Brent
Prep Club for GRE Bot
gmatclubot
Re: 4 - x^2 [#permalink]
14 Feb 2023, 00:26
Moderators:
adewale223
GRE Instructor
84 posts
bronaugust
GRE Forum Moderator
37 posts
BrushMyQuant
Moderator
1111 posts
VibhuAnurag
GRE Instructor
234 posts

Powered by phpBB © phpBB Group | Emoji artwork provided by EmojiOne

Main navigation

Partners

GRE Resources

www.ets.org/gre | About | Terms and Conditions and Privacy Policy | Prep Club for GRE Rules | Contact