It is currently 19 Nov 2017, 19:25

### 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

# Events & Promotions

###### Events & Promotions in June
Open Detailed Calendar

# What is the value of a^3+b^3-c^3+3abc/a^2+b^2+c^2+ac+bc-ab

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

### Hide Tags

Director
Joined: 03 Sep 2006
Posts: 864

Kudos [?]: 1106 [2], given: 33

What is the value of a^3+b^3-c^3+3abc/a^2+b^2+c^2+ac+bc-ab [#permalink]

### Show Tags

24 Jan 2012, 09:59
2
This post received
KUDOS
4
This post was
BOOKMARKED
00:00

Difficulty:

45% (medium)

Question Stats:

69% (01:38) correct 31% (02:13) wrong based on 114 sessions

### HideShow timer Statistics

What is the value of $$\frac{a^3+b^3-c^3+3abc}{a^2+b^2+c^2+ac+bc-ab}$$?

A. a+b-c
B. a-b+c
C. -a+b+c
D. a-b-c
E. -a+b-c
[Reveal] Spoiler: OA

Kudos [?]: 1106 [2], given: 33

Math Expert
Joined: 02 Sep 2009
Posts: 42259

Kudos [?]: 132730 [1], given: 12335

Re: Simplest form of expression [#permalink]

### Show Tags

24 Jan 2012, 11:26
1
This post received
KUDOS
Expert's post
1
This post was
BOOKMARKED
LM wrote:
What is the value of $$\frac{a^3+b^3-c^3+3abc}{a^2+b^2+c^2+ac+bc-ab}?$$

A) a+b-c

B) a-b+c

C) -a+b+c

D) a-b-c

E) -a+b-c

Plug-in method would be the most efficient way to deal with this problem.

Let $$a=2$$, $$b=1$$ and $$c=0$$. Then $$\frac{a^3+b^3-c^3+3abc}{a^2+b^2+c^2+ac+bc-ab}=3$$. Now let's see which answer choice yields 3:

A. a+b-c=3 --> correct;
B. a-b+c=1 --> discard;
C. -a+b+c=-1 --> discard;
D. a-b-c=1 --> discard;
E. -a+b-c=-1 --> discard.

Answer: A.

P.S. For plug-in method it might happen that for some particular numbers more than one option may give "correct" answer. In this case just pick some other numbers and check again these "correct" options only.

Hope it helps.
_________________

Kudos [?]: 132730 [1], given: 12335

SVP
Status: The Best Or Nothing
Joined: 27 Dec 2012
Posts: 1852

Kudos [?]: 2713 [4], given: 193

Location: India
Concentration: General Management, Technology
WE: Information Technology (Computer Software)
What is the value of a^3+b^3-c^3+3abc/a^2+b^2+c^2+ac+bc-ab [#permalink]

### Show Tags

14 Jul 2014, 22:38
4
This post received
KUDOS
1
This post was
BOOKMARKED
$$\frac{a^3+b^3-c^3+3abc}{a^2+b^2+c^2+ac+bc-ab}$$

This also means that $$a^2+b^2+c^2+ac+bc-ab$$ when multiplied with any one of the 5 options, gives answer $$a^3+b^3-c^3+3abc$$

Just focus on $$a^2, b^2, c^2$$ in the LHS & $$a^3+b^3-c^3$$ on RHS

$$a^2$$ has to be multiplied by "a" to give $$a^3$$

Similarly,$$b^{2} * b = b^3$$

$$c^{2} * -c = -c^3$$

Answer = a+b-c

Answer = A
_________________

Kindly press "+1 Kudos" to appreciate

Kudos [?]: 2713 [4], given: 193

Non-Human User
Joined: 09 Sep 2013
Posts: 15658

Kudos [?]: 282 [0], given: 0

Re: What is the value of a^3+b^3-c^3+3abc/a^2+b^2+c^2+ac+bc-ab [#permalink]

### Show Tags

01 Jan 2017, 14:07
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.
_________________

Kudos [?]: 282 [0], given: 0

Re: What is the value of a^3+b^3-c^3+3abc/a^2+b^2+c^2+ac+bc-ab   [#permalink] 01 Jan 2017, 14:07
Display posts from previous: Sort by

# What is the value of a^3+b^3-c^3+3abc/a^2+b^2+c^2+ac+bc-ab

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

 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®.