Summer is Coming! Join the Game of Timers Competition to Win Epic Prizes. Registration is Open. Game starts Mon July 1st.

It is currently 17 Jul 2019, 01:41

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

If one root of the equation 2x^2 + 3x – k = 0 is 6, what is the value

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

Hide Tags

Find Similar Topics 
Manager
Manager
avatar
Joined: 19 Oct 2010
Posts: 162
Location: India
GMAT 1: 560 Q36 V31
GPA: 3
GMAT ToolKit User
If one root of the equation 2x^2 + 3x – k = 0 is 6, what is the value  [#permalink]

Show Tags

New post 17 Apr 2011, 09:17
1
1
00:00
A
B
C
D
E

Difficulty:

  15% (low)

Question Stats:

76% (01:15) correct 24% (02:22) wrong based on 134 sessions

HideShow timer Statistics


If one root of the equation 2x^2 + 3x – k = 0 is 6, what is the value of k?

(A) 90
(B) 42
(C) 18
(D) 10
(E) –10

_________________
petrifiedbutstanding
Retired Moderator
avatar
B
Joined: 16 Nov 2010
Posts: 1360
Location: United States (IN)
Concentration: Strategy, Technology
Reviews Badge
Re: If one root of the equation 2x^2 + 3x – k = 0 is 6, what is the value  [#permalink]

Show Tags

New post 17 Apr 2011, 09:26
Because 6 is a root, the following is true :

2* 6^2 + 3*6 - k = 0

=> k = 72 + 18 = 90

Answer - A
_________________
Formula of Life -> Achievement/Potential = k * Happiness (where k is a constant)

GMAT Club Premium Membership - big benefits and savings
Manager
Manager
avatar
Joined: 18 Jan 2011
Posts: 214
Re: If one root of the equation 2x^2 + 3x – k = 0 is 6, what is the value  [#permalink]

Show Tags

New post 17 Apr 2011, 13:33
nice,I used the roots equation :P
=> 6 = (-3 + sqrt(9+8K))/2*2
=> k = 90
So, A
_________________
Good Luck!!!

***Help and be helped!!!****
Manager
Manager
avatar
Joined: 03 Mar 2011
Posts: 86
Location: United States
Schools: Erasmus (S)
GMAT 1: 730 Q51 V37
GPA: 3.9
Re: ps 6.7  [#permalink]

Show Tags

New post 06 Jul 2011, 00:47
1
We just enter this root into the equation in order to recieve an equation to find the answer!

2*6^2+3*6-k=0
k=72+18=90

The answer is A
_________________

If my post is useful for you not be ashamed to KUDO me!
Let kudo each other!

GMAT Tutor
avatar
G
Joined: 24 Jun 2008
Posts: 1727
Re: ps 6.7  [#permalink]

Show Tags

New post 06 Jul 2011, 01:01
1
1
racejockey wrote:
If one root of the equation 2x2 + 3x – k = 0 is 6, what is the value of k?
(A) 90
(B) 42
(C) 18
(D) 10
(E) –10


The question should say that k is a constant. In that case, if 6 is a 'root' of the equation, that just means that x=6 is one solution to the equation. So we can plug in x=6:
\(\begin{align*}
2x^2 + 3x - k &= 0 \\
2(6^2) + (3)(6) - k &= 0 \\
72 + 18 &= k \\
90 &= k
\end{align*}\)
_________________
GMAT Tutor in Toronto

If you are looking for online GMAT math tutoring, or if you are interested in buying my advanced Quant books and problem sets, please contact me at ianstewartgmat at gmail.com
Manager
Manager
User avatar
Joined: 10 Jun 2015
Posts: 117
Re: If one root of the equation 2x^2 + 3x – k = 0 is 6, what is the value  [#permalink]

Show Tags

New post 22 Aug 2015, 05:28
petrifiedbutstanding wrote:
If one root of the equation 2x^2 + 3x – k = 0 is 6, what is the value of k?

(A) 90
(B) 42
(C) 18
(D) 10
(E) –10


let the other root is 'a'
a +6=-3/2; a = -15/2
6a = -k/2
implies k=90
Non-Human User
User avatar
Joined: 09 Sep 2013
Posts: 11667
Re: If one root of the equation 2x^2 + 3x – k = 0 is 6, what is the value  [#permalink]

Show Tags

New post 23 Nov 2018, 08:45
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
Re: If one root of the equation 2x^2 + 3x – k = 0 is 6, what is the value   [#permalink] 23 Nov 2018, 08:45
Display posts from previous: Sort by

If one root of the equation 2x^2 + 3x – k = 0 is 6, what is the value

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





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