NEW HERE? LEARN MORE
closeclose
Last visit was: 26 Apr 2024, 00:01 It is currently 26 Apr 2024, 00:01
Decision Tracker
My Rewards
New posts
New comers' posts

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.
Go to My Error Log Learn more
Close
Request Expert Reply
Confirm Cancel

If x^2 + 0.25x - 0.5 = 0, then x(4x + 1) =

SORT BY:
Date
Kudos
Tags:
Find Similar Topics 
Show Tags
Hide Tags
User avatar
L
Bunuel
Math Expert
Joined: 02 Sep 2009
Posts: 92915
Own Kudos [?]: 619076 [2]
Given Kudos: 81595
Send PM
CAT Tests Forum Quiz Mode
If x^2 + 0.25x - 0.5 = 0, then x(4x + 1) = [#permalink] New post   17 Sep 2017, 03:45
2
Bookmarks
Expert Reply
00:00
A
B
C
D
E

Difficulty:

25% (medium)

Question Stats:

79% (01:18) correct 21% (02:29) wrong based on 86 sessions
Hide Show timer Statistics
If x^2 + 0.25x - 0.5 = 0, then x(4x + 1) =

A. 0.5
B. 2
C. 3.5
D. 4
E. 0
ShowHide Answer
Official Answer
B
avatar
B
kaulshanx
Intern
Intern
Joined: 19 Sep 2016
Posts: 29
Own Kudos [?]: 3 [0]
Given Kudos: 3
Send PM
Re: If x^2 + 0.25x - 0.5 = 0, then x(4x + 1) = [#permalink] New post   17 Sep 2017, 04:09
X(x+.25)=.5, either x=.5 or x=.25. Now substituting these values in the required equation, x(4x+1)= either 1.5 or .5. So answer is A.

Sent from my SM-N920G using GMAT Club Forum mobile app
avatar
B
kaulshanx
Intern
Intern
Joined: 19 Sep 2016
Posts: 29
Own Kudos [?]: 3 [0]
Given Kudos: 3
Send PM
Re: If x^2 + 0.25x - 0.5 = 0, then x(4x + 1) = [#permalink] New post   17 Sep 2017, 04:47
Sorry. Correcting the answer is B i.e. 2

Sent from my SM-N920G using GMAT Club Forum mobile app
User avatar
B
Arsh4MBA
Manager
Manager
Joined: 19 Jul 2017
Posts: 71
Own Kudos [?]: 25 [0]
Given Kudos: 85
Location: India
Concentration: General Management, Strategy
GPA: 3.5
Send PM
Re: If x^2 + 0.25x - 0.5 = 0, then x(4x + 1) = [#permalink] New post   17 Sep 2017, 07:55
Bunuel wrote:
If x^2 + 0.25x - 0.5 = 0, then x(4x + 1) =

A. 0.5
B. 2
C. 3.5
D. 4
E. 0


x^2+1/4x= 1/2;

4x^2+x= 2 ==> x(4x+1)= 2

Ans:B
User avatar
L
generis
Senior SC Moderator
Joined: 22 May 2016
Posts: 5330
Own Kudos [?]: 35491 [0]
Given Kudos: 9464
Send PM
CAT Tests
If x^2 + 0.25x - 0.5 = 0, then x(4x + 1) = [#permalink] New post   17 Sep 2017, 15:01
Expert Reply
Bunuel wrote:
If x^2 + 0.25x - 0.5 = 0, then x(4x + 1) =

A. 0.5
B. 2
C. 3.5
D. 4
E. 0

\(x^2 + 0.25x - 0.5 = 0\)

Multiply by 4: prompt's second expression is a factored version of \(4x^2 + x\). That expression = \((4)(x^2 + 0.25x)\) -- i.e., (4) * the first two terms of the quadratic equation

\((4)x^2 + (4)0.25x - (4)0.5 = 0\)
\(4x^2 + x - 2 = 0\)
\(4x^2 + x = 2\)
\(x(4x + 1) = 2\)

Answer B
avatar
B
Shanks1
Intern
Intern
Joined: 11 Aug 2014
Posts: 8
Own Kudos [?]: 5 [0]
Given Kudos: 1
Location: United States
Concentration: International Business, Leadership
Schools: HBS '18 IE Sept'16 CBS '20 Insead Sept'18
WE:Consulting (Investment Banking)
Send PM
Re: If x^2 + 0.25x - 0.5 = 0, then x(4x + 1) = [#permalink] New post   18 Sep 2017, 11:53
x^2 + .25x -.5=0
can be written as x^2 + x/4 -5/10=0
now, x( x+1/4)=5/10
multiple by 4 on both sides
you get 4x^2+x=2 i.e x(4x+1)=2
User avatar
B
ankita09
Intern
Intern
Joined: 04 Jun 2015
Posts: 23
Own Kudos [?]: 11 [0]
Given Kudos: 38
Location: India
Concentration: General Management, Operations
GMAT 1: 640 Q49 V28
GPA: 4
WE:Programming (Computer Software)
Send PM
Reviews Badge
Re: If x^2 + 0.25x - 0.5 = 0, then x(4x + 1) = [#permalink] New post   18 Sep 2017, 12:03
x^2 + (x/4) =1/2
x(4x +1) = 2 so Ans is B.
User avatar
L
ScottTargetTestPrep
Target Test Prep Representative
Joined: 14 Oct 2015
Status:Founder & CEO
Affiliations: Target Test Prep
Posts: 18761
Own Kudos [?]: 22055 [0]
Given Kudos: 283
Location: United States (CA)
Send PM
Re: If x^2 + 0.25x - 0.5 = 0, then x(4x + 1) = [#permalink] New post   22 Sep 2017, 11:45
Expert Reply
Bunuel wrote:
If x^2 + 0.25x - 0.5 = 0, then x(4x + 1) =

A. 0.5
B. 2
C. 3.5
D. 4
E. 0


We need to determine the value of x(4x + 1) = 4x^2 + x.

Multiplying the equation x^2 + 0.25x - 0.5 = 0 by 4, we have:

4x^2 + x - 2 = 0

4x^2 + x = 2

Answer: B
User avatar
bumpbot
Non-Human User
Joined: 09 Sep 2013
Posts: 32680
Own Kudos [?]: 822 [0]
Given Kudos: 0
Send PM
Re: If x^2 + 0.25x - 0.5 = 0, then x(4x + 1) = [#permalink] New post   29 May 2023, 13:43
Hello from the GMAT Club BumpBot!

Thanks to another GMAT Club member, I have just discovered this valuable topic, yet it had no discussion for over a year. I am now bumping it up - doing my job. I think you may find it valuable (esp those replies with Kudos).

Want to see all other topics I dig out? Follow me (click follow button on profile). You will receive a summary of all topics I bump in your profile area as well as via email.
GMAT Club Bot
gmatclubot
Re: If x^2 + 0.25x - 0.5 = 0, then x(4x + 1) = [#permalink]
29 May 2023, 13:43
Moderators:
Bunuel
Math Expert
92915 posts
yashikaaggarwal
Senior Moderator - Masters Forum
3137 posts

Powered by phpBB © phpBB Group | Emoji artwork provided by EmojiOne
Main navigation
GMAT Resources
Partners
MBA Resources
www.gmac.com|www.mba.com | | GMAT Club Rules | Terms and Conditions