GMAT Question of the Day - Daily to your Mailbox; hard ones only

It is currently 20 Feb 2019, 15:45

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.

Close

Request Expert Reply

Confirm Cancel
Events & Promotions in February
PrevNext
SuMoTuWeThFrSa
272829303112
3456789
10111213141516
17181920212223
242526272812
Open Detailed Calendar
  • Free GMAT Prep Hour

     February 20, 2019

     February 20, 2019

     08:00 PM EST

     09:00 PM EST

    Strategies and techniques for approaching featured GMAT topics. Wednesday, February 20th at 8 PM EST
  • Online GMAT boot camp for FREE

     February 21, 2019

     February 21, 2019

     10:00 PM PST

     11:00 PM PST

    Kick off your 2019 GMAT prep with a free 7-day boot camp that includes free online lessons, webinars, and a full GMAT course access. Limited for the first 99 registrants! Feb. 21st until the 27th.

What is the value of b If 2x − 1 is a factor of 2x^2 + bx + 3 ?

  new topic post reply Question banks Downloads My Bookmarks Reviews Important topics  
Author Message
TAGS:

Hide Tags

 
Intern
Intern
avatar
B
Joined: 12 Jan 2019
Posts: 7
What is the value of b If 2x − 1 is a factor of 2x^2 + bx + 3 ?  [#permalink]

Show Tags

New post Updated on: 03 Feb 2019, 01:15
1
00:00
A
B
C
D
E

Difficulty:

  45% (medium)

Question Stats:

59% (01:58) correct 41% (01:55) wrong based on 27 sessions

HideShow timer Statistics

What is the value of b If 2x − 1 is a factor of 2x^2 + bx + 3 ?

A. -7
B. -3
C. -1
D. 3
E. 7

Originally posted by Nums99 on 02 Feb 2019, 05:24.
Last edited by Bunuel on 03 Feb 2019, 01:15, edited 1 time in total.
Renamed the topic and edited the question.
VP
VP
avatar
G
Joined: 09 Mar 2018
Posts: 1001
Location: India
Re: What is the value of b If 2x − 1 is a factor of 2x^2 + bx + 3 ?  [#permalink]

Show Tags

New post 02 Feb 2019, 05:58
2
Nums99 wrote:
What is the value of b If 2x − 1 is a factor of 2x^2 +bx +3 ?
a) -7
b)-3
c)-1
d)3
e)7

please help!!!


If some expression is a factor of a quadratic equation, this means that it will satisfy it

2x-1=0

x=1/2

Put the value of x in the quadratic equation
1/2 + b/2 + 3 =0
b = -7
_________________

If you notice any discrepancy in my reasoning, please let me know. Lets improve together.

Quote which i can relate to.
Many of life's failures happen with people who do not realize how close they were to success when they gave up.

Intern
Intern
avatar
B
Joined: 08 Oct 2017
Posts: 31
GMAT ToolKit User
Re: What is the value of b If 2x − 1 is a factor of 2x^2 + bx + 3 ?  [#permalink]

Show Tags

New post 02 Feb 2019, 07:57
1
Quadratic equation 2x^+bx+3 = 0

Factors (2x-1)*(2nd factor) = 2x^+bx+3= 0

(2x-1) = 0 ==>> x = 1/2

plug in value of x into quadratic equation to determine value of b. You can take it from here.

Give me Kudos to get my GMAT club test access****

Nums99 wrote:
What is the value of b If 2x − 1 is a factor of 2x^2 +bx +3 ?
a) -7
b)-3
c)-1
d)3
e)7

please help!!!

_________________

****Give me Kudos to get my GMAT club test access****

RC Moderator
User avatar
D
Joined: 24 Aug 2016
Posts: 676
Location: Canada
Concentration: Entrepreneurship, Operations
GMAT 1: 630 Q48 V28
GMAT 2: 540 Q49 V16
GMAT ToolKit User Premium Member Reviews Badge CAT Tests
Re: What is the value of b If 2x − 1 is a factor of 2x^2 + bx + 3 ?  [#permalink]

Show Tags

New post 02 Feb 2019, 09:33
1
According to the Q: 2x − 1 =0 ==>\(x=\frac{1}{2}\)
Hence \(b=-2x-\frac{3}{x}\) =-1-3.2 = -7 Ans A

Just 1 point Nums99 .... in the Q you mentioned an expression not an equation.
To clarify : 2x^2 +bx +3 is an expression & on contracy 2x^2 +bx +3 =0 is an equation.
All the solutions are done assuming you mentioned an eqn: 2x^2 +bx +3 =0
If the Q is about only the expression .....in my view the Q does not stand :-)
_________________

Please let me know if I am going in wrong direction.
Thanks in appreciation.

Intern
Intern
avatar
B
Joined: 14 May 2018
Posts: 41
GMAT 1: 710 Q49 V38
Re: What is the value of b If 2x − 1 is a factor of 2x^2 + bx + 3 ?  [#permalink]

Show Tags

New post 02 Feb 2019, 10:25
1
Nums99 wrote:
What is the value of b If 2x − 1 is a factor of 2x^2 +bx +3 ?
a) -7
b)-3
c)-1
d)3
e)7

please help!!!


If 2x-1 is a factor, then it means that 2x-1=0 ==> x=1/2

Now put x=1/2 in the equation 2x^2+bx+3=0

2*1/4+1/2b+3=0
Solving, b=-7

Ans:A
_________________

Now that I am done with my College Applications, I will try and be more regular here and help out aspirants and give back to this wonderful community. Please hit kudos if you like my answers.

GMAT:710 (Q49,V38,IR8,AWA5)

Director
Director
User avatar
V
Joined: 11 Feb 2015
Posts: 719
Premium Member CAT Tests
Re: What is the value of b If 2x − 1 is a factor of 2x^2 + bx + 3 ?  [#permalink]

Show Tags

New post 20 Feb 2019, 08:31
Nums99 wrote:
What is the value of b If 2x − 1 is a factor of 2x^2 + bx + 3 ?

A. -7
B. -3
C. -1
D. 3
E. 7


If someone got stuck and could not proceed as per the solutions mentioned above then you may work backward; One could use answer options and substitute for the value of b. Since 2x-1 is a factor, you would realize that only option A works.
_________________

"Please hit :thumbup: +1 Kudos if you like this post" :student_man:

_________________
Manish :geek:

"Only I can change my life. No one can do it for me"

GMAT Club Bot
Re: What is the value of b If 2x − 1 is a factor of 2x^2 + bx + 3 ?   [#permalink] 20 Feb 2019, 08:31
Display posts from previous: Sort by

What is the value of b If 2x − 1 is a factor of 2x^2 + bx + 3 ?

  new topic post reply Question banks Downloads My Bookmarks Reviews Important topics  


Copyright

GMAT Club MBA Forum Home| About| Terms and Conditions and Privacy Policy| GMAT Club Rules| Contact| Sitemap

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

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®.