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

It is currently 15 Oct 2019, 19:20

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

What is the value of |x + 4|?

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

Hide Tags

Find Similar Topics 
Math Expert
User avatar
V
Joined: 02 Sep 2009
Posts: 58340
What is the value of |x + 4|?  [#permalink]

Show Tags

New post 18 Jun 2015, 03:18
2
4
00:00
A
B
C
D
E

Difficulty:

  55% (hard)

Question Stats:

58% (01:14) correct 42% (01:17) wrong based on 288 sessions

HideShow timer Statistics

CEO
CEO
User avatar
D
Status: GMATINSIGHT Tutor
Joined: 08 Jul 2010
Posts: 2974
Location: India
GMAT: INSIGHT
Schools: Darden '21
WE: Education (Education)
Reviews Badge
What is the value of |x + 4|?  [#permalink]

Show Tags

New post 18 Jun 2015, 06:47
2
1
Bunuel wrote:
What is the value of |x + 4|?

(1) x^2 + 8x + 12 = 0
(2) x^2 + 6x = 0

Kudos for a correct solution.


Question : |x + 4| = ?

Statement 1: x^2 + 8x + 12 = 0

x^2 + 6x + 2x + 12 = 0
i.e. (x+6)(x+2) = 0
i.e. x = -2 or -6

i.e. |x + 4| = |-2 + 4| or |-6 + 4| = 2

SUFFICIENT

Statement 2: x^2 + 6x = 0

i.e. x(x+6) = 0
i.e. x = 0 or 6

i.e. |x + 4| = |0 + 4| or |-6 + 4| = 4 or 2

NOT SUFFICIENT

Answer: Option
_________________
Prosper!!!
GMATinsight
Bhoopendra Singh and Dr.Sushma Jha
e-mail: info@GMATinsight.com I Call us : +91-9999687183 / 9891333772
Online One-on-One Skype based classes and Classroom Coaching in South and West Delhi
http://www.GMATinsight.com/testimonials.html

ACCESS FREE GMAT TESTS HERE:22 ONLINE FREE (FULL LENGTH) GMAT CAT (PRACTICE TESTS) LINK COLLECTION
Intern
Intern
avatar
Joined: 01 Jan 2015
Posts: 17
Re: What is the value of |x + 4|?  [#permalink]

Show Tags

New post 18 Jun 2015, 07:58
Bunuel wrote:
What is the value of |x + 4|?

(1) x^2 + 8x + 12 = 0
(2) x^2 + 6x = 0

Kudos for a correct solution.



From 1) simplyfying the equation, (x+2) (x+6) = 0 , Insufficient
fROM 2) x (x+6) = 0 , Insufficient.

1 + 2 we infer x+6 = 0 & x=-6. |x + 4| = 2. Hence C
CEO
CEO
User avatar
D
Status: GMATINSIGHT Tutor
Joined: 08 Jul 2010
Posts: 2974
Location: India
GMAT: INSIGHT
Schools: Darden '21
WE: Education (Education)
Reviews Badge
Re: What is the value of |x + 4|?  [#permalink]

Show Tags

New post 18 Jun 2015, 08:01
NavenRk wrote:
Bunuel wrote:
What is the value of |x + 4|?

(1) x^2 + 8x + 12 = 0
(2) x^2 + 6x = 0

Kudos for a correct solution.



From 1) simplyfying the equation, (x+2) (x+6) = 0 , Insufficient
fROM 2) x (x+6) = 0 , Insufficient.

1 + 2 we infer x+6 = 0 & x=-6. |x + 4| = 2. Hence C


Hi NaveenRK,

Looks like you didn't try to calculate the value of |x + 4| by substituting the two values obtained from the First statement.

Fortunately Both values obtained from Statement 1 result in the identical value of |x + 4| hence Statement 1 Alone is SUFFICIENT
_________________
Prosper!!!
GMATinsight
Bhoopendra Singh and Dr.Sushma Jha
e-mail: info@GMATinsight.com I Call us : +91-9999687183 / 9891333772
Online One-on-One Skype based classes and Classroom Coaching in South and West Delhi
http://www.GMATinsight.com/testimonials.html

ACCESS FREE GMAT TESTS HERE:22 ONLINE FREE (FULL LENGTH) GMAT CAT (PRACTICE TESTS) LINK COLLECTION
Intern
Intern
avatar
Joined: 29 Mar 2015
Posts: 44
Location: United States
GMAT ToolKit User Reviews Badge
Re: What is the value of |x + 4|?  [#permalink]

Show Tags

New post 18 Jun 2015, 23:53
1
Bunuel wrote:
What is the value of |x + 4|?

(1) x^2 + 8x + 12 = 0
(2) x^2 + 6x = 0

Kudos for a correct solution.


1: factors to (x+6)(x+2) -> x = -6 or -2. so |x+4| = either |-6+4|=|-2|=2 or |-2+4|=|2|=2. Sufficient.
2: factors to x(x+6)=0. x can be 0 or -6. |x+4| can either be 2 from above, or |0+4|=4 if x=0. Insufficient.
Answer is A>
Math Expert
User avatar
V
Joined: 02 Sep 2009
Posts: 58340
Re: What is the value of |x + 4|?  [#permalink]

Show Tags

New post 22 Jun 2015, 05:38
1
Bunuel wrote:
What is the value of |x + 4|?

(1) x^2 + 8x + 12 = 0
(2) x^2 + 6x = 0

Kudos for a correct solution.


MANHATTAN GMAT OFFICIAL SOLUTION:

Statement (1) tells us that x^2 + 8x + 12 = 0. Factoring:
(x + 2)(x + 6) = 0
x = –2 or –6

The question asks for the value of |x + 4|. At first glance, it might appear that we have 2 values for x, and thus do not know the value of |x + 4|. However:
|(–2) + 4| = |2| = 2 |(–6) + 4| = |–2| = 2

Therefore Statement (1) is SUFFICIENT.

Statement (2) tells us that x^2 + 6x = 0. Factoring:
x(x + 6) = 0
x = 0 or –6

Testing both values for x:
|(0) + 4| = 4 |(–6) + 4| = |–2| = 2

We get two different values for x, so Statement (2) is INSUFFICIENT.

If we had not Computed to Completion, we might have fallen into the trap of thinking that because Statement (1) gave us two values for x, we would get two different answers to the question. That was not the case: we got the same answer from both values.

The correct answer is A.
_________________
Non-Human User
User avatar
Joined: 09 Sep 2013
Posts: 13168
Re: What is the value of |x + 4|?  [#permalink]

Show Tags

New post 16 Aug 2018, 02:22
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: What is the value of |x + 4|?   [#permalink] 16 Aug 2018, 02:22
Display posts from previous: Sort by

What is the value of |x + 4|?

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





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