It is currently 22 Feb 2018, 08:59

TODAY:

MIT Sloan Releasing 1st Wave of Interview Invites - Join GMATClub CHAT for Live Updates


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

Events & Promotions in June
Open Detailed Calendar

If 4x−3y=10 and 7x−8y=34 , what is the value x−y ?

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

Hide Tags

Expert Post
Math Expert
User avatar
V
Joined: 02 Sep 2009
Posts: 43866
If 4x−3y=10 and 7x−8y=34 , what is the value x−y ? [#permalink]

Show Tags

New post 01 Mar 2017, 04:41
Expert's post
1
This post was
BOOKMARKED
00:00
A
B
C
D
E

Difficulty:

  15% (low)

Question Stats:

81% (02:03) correct 19% (01:46) wrong based on 99 sessions

HideShow timer Statistics

Expert Post
Top Contributor
1 KUDOS received
SVP
SVP
User avatar
P
Joined: 11 Sep 2015
Posts: 2055
Location: Canada
Re: If 4x−3y=10 and 7x−8y=34 , what is the value x−y ? [#permalink]

Show Tags

New post 01 Mar 2017, 04:50
1
This post received
KUDOS
Expert's post
Top Contributor
2
This post was
BOOKMARKED
Bunuel wrote:
If 4x−3y=10 and 7x−8y=34, what is the value x−y?

A. 2
B. 4
C. 6
D. 8
E. 12


Nice question!

The long approach is to solve the system for the INDIVIDUAL values of x and y and then use those values to determine the value of x-y.

The quick approach is to ADD the two equations (4x−3y=10 and 7x−8y=34) to get: 11x - 11y = 44
Then divide both sides by 11 to get: x - y = 4

Answer: B

Cheers,
Brent
_________________

Brent Hanneson – Founder of gmatprepnow.com

Image

Board of Directors
User avatar
G
Status: QA & VA Forum Moderator
Joined: 11 Jun 2011
Posts: 3326
Location: India
GPA: 3.5
WE: Business Development (Commercial Banking)
GMAT ToolKit User Premium Member
Re: If 4x−3y=10 and 7x−8y=34 , what is the value x−y ? [#permalink]

Show Tags

New post 01 Mar 2017, 10:44
Bunuel wrote:
If 4x−3y=10 and 7x−8y=34, what is the value x−y?

A. 2
B. 4
C. 6
D. 8
E. 12


\(4x − 3y = 10 ---------------> (I)\)
\(7x − 8y = 34 ---------------> (II)\)

Add (I) and (II)

\(11x − 11y = 44\)

Or, \(x − y = 4\)

Thus, answer must be (B) 4
_________________

Thanks and Regards

Abhishek....

PLEASE FOLLOW THE RULES FOR POSTING IN QA AND VA FORUM AND USE SEARCH FUNCTION BEFORE POSTING NEW QUESTIONS

How to use Search Function in GMAT Club | Rules for Posting in QA forum | Writing Mathematical Formulas |Rules for Posting in VA forum | Request Expert's Reply ( VA Forum Only )

Expert Post
1 KUDOS received
Target Test Prep Representative
User avatar
S
Status: Head GMAT Instructor
Affiliations: Target Test Prep
Joined: 04 Mar 2011
Posts: 2001
Re: If 4x−3y=10 and 7x−8y=34 , what is the value x−y ? [#permalink]

Show Tags

New post 02 Mar 2017, 17:40
1
This post received
KUDOS
Expert's post
Bunuel wrote:
If 4x−3y=10 and 7x−8y=34, what is the value x−y?

A. 2
B. 4
C. 6
D. 8
E. 12


Adding the two equations together, we have:

4x - 3y = 10

7x - 8y = 34

11x - 11y = 44

Dividing both sides by 11, we have:

x - y = 4

Answer: B
_________________

Jeffery Miller
Head of GMAT Instruction

GMAT Quant Self-Study Course
500+ lessons 3000+ practice problems 800+ HD solutions

Re: If 4x−3y=10 and 7x−8y=34 , what is the value x−y ?   [#permalink] 02 Mar 2017, 17:40
Display posts from previous: Sort by

If 4x−3y=10 and 7x−8y=34 , what is the value x−y ?

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


GMAT Club MBA Forum Home| About| Terms and Conditions| 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®.