Find all School-related info fast with the new School-Specific MBA Forum
Learn more about the recent changes... close

It is currently 24 May 2013, 00:20
Customize  |  Hide

Search
Register
New posts
Unanswered

If 2x^2 –y^2 = 2xy

  Question banks Downloads My Bookmarks Reviews  
  Oldest Best Reply
Search for:
 
Print view
First unread post
Author Message
TAGS:
Manager
Manager
User avatar
Joined: 06 Feb 2010
Posts: 105
Schools: University of Dhaka - Class of 2010
GPA: 3.63
WE: Business Development (Consumer Products)
Followers: 22

Kudos [?]: 343 [0], given: 150

GMAT Tests User
If 2x^2 –y^2 = 2xy [#permalink] New post 11 Nov 2010, 22:38
00:00

Question Stats:

10% (00:00) correct 90% (01:46) wrong based on 0 sessions
If 2x^2 –y^2 = 2xy, then (x+y)^2=

(A) X^2
(B) 3x^2
(C) 4xy
(D) 2y^2
(E) –y^2
_________________

Practice Makes a Man Perpect....Practice. Practice. Practice......Perfectly

Critical Reasoning: best-critical-reasoning-shortcuts-notes-tips-91280.html

Collections of MGMAT CAT: collections-of-mgmat-cat-math-152750.html

MGMAT SC SUMMARY: mgmat-sc-summary-of-fourth-edition-152753.html

Sentence Correction: sentence-correction-strategies-and-notes-91218.html

Arithmatic & Algebra: arithmatic-algebra-93678.html

Helpful Geometry formula sheet: best-geometry-93676.html

I hope these will help to understand the basic concepts & strategies. Please Click ON KUDOS Button.

1 KUDOS received
GMAT Club team member
User avatar
Joined: 02 Sep 2009
Posts: 11594
Followers: 1800

Kudos [?]: 9588 [1] , given: 826

GMAT Tests User CAT Tests
Top Member of the Month
Re: If 2x^2 –y^2 = 2xy [#permalink] New post 12 Nov 2010, 00:21
1
This post received
KUDOS
monirjewel wrote:
If 2x^2 –y^2 = 2xy, then (x+y)^2=

(A) X^2
(B) 3x^2
(C) 4xy
(D) 2y^2
(E) –y^2


Given: 2xy=2x^2-y^2 --> (x+y)^2=x^2+2xy+y^2=x^2+(2x^2-y^2)+y^2=3x^2.

Answer: B.
_________________

PLEASE READ AND FOLLOW: 11 Rules for Posting!!!

RESOURCES: [GMAT MATH BOOK]; 1. Triangles; 2. Polygons; 3. Coordinate Geometry; 4. Factorials; 5. Circles; 6. Number Theory

COLLECTION OF QUESTIONS:
PS: 1. Tough and Tricky questions; 2. Hard questions; 3. Hard questions part 2; 4. Standard deviation; 5. Tough Problem Solving Questions With Solutions; 6. Probability and Combinations Questions With Solutions; 7 Tough and tricky exponents and roots questions; 8 12 Easy Pieces (or not?); 9 Bakers' Dozen; 10 Algebra set. NEW!!!

DS: 1. DS tough questions; 2. DS tough questions part 2; 3. DS tough questions part 3; 4. DS Standard deviation; 5. Inequalities; 6. 700+ GMAT Data Sufficiency Questions With Explanations; 7 Tough and tricky exponents and roots questions; 8 The Discreet Charm of the DS ; 9 Devil's Dozen!!!; 10 Number Properties set. NEW!!!


What are GMAT Club Tests?
25 extra-hard Quant Tests

Find out what's new at GMAT Club - latest features and updates

Manager
Manager
User avatar
Joined: 01 Nov 2010
Posts: 185
Location: Zürich, Switzerland
Followers: 2

Kudos [?]: 11 [0], given: 20

Re: If 2x^2 –y^2 = 2xy [#permalink] New post 12 Nov 2010, 14:46
2x^2 –y^2 = 2xy
2x^2 = 2xy+y^2

3x^2 = x^2 + 2xy+y^2 (adding x^2 on both sides)

3x^2 = (x+y)^2


Answer:- B
Manager
Manager
User avatar
Joined: 25 Jan 2010
Posts: 119
Location: Calicut, India
Followers: 5

Kudos [?]: 42 [0], given: 40

Re: If 2x^2 –y^2 = 2xy [#permalink] New post 12 Nov 2010, 17:30
2x^2-y^2=2xy

(x+y)^2= x^2+2xy+y^2

replace 2xy by 2x^2-y^2 and solve

Answer B.
_________________

If u think this post is useful plz feed me with a kudo

Manager
Manager
Joined: 23 Oct 2009
Posts: 71
Followers: 1

Kudos [?]: 8 [0], given: 14

Re: If 2x^2 –y^2 = 2xy [#permalink] New post 29 Dec 2010, 13:08
Sarang wrote:
2x^2 –y^2 = 2xy
2x^2 = 2xy+y^2

3x^2 = x^2 + 2xy+y^2 (adding x^2 on both sides)

3x^2 = (x+y)^2


Answer:- B


i didn't understand this pls explain
_________________

Consider giving Kudos if you liked my post. Thanks!

GMAT Club team member
User avatar
Joined: 02 Sep 2009
Posts: 11594
Followers: 1800

Kudos [?]: 9588 [0], given: 826

GMAT Tests User CAT Tests
Top Member of the Month
Re: If 2x^2 –y^2 = 2xy [#permalink] New post 29 Dec 2010, 13:33
rahul321 wrote:
Sarang wrote:
2x^2 –y^2 = 2xy
2x^2 = 2xy+y^2

3x^2 = x^2 + 2xy+y^2 (adding x^2 on both sides)

3x^2 = (x+y)^2


Answer:- B


i didn't understand this pls explain


Given: 2x^2-y^2=2xy --> rearrange: 2x^2=2xy+y^2 --> add x^2 to both parts of the equation: 2x^2+x^2=x^2+2xy+y^2 --> 3x^2=(x+y)^2.

Hope it's clear.
_________________

PLEASE READ AND FOLLOW: 11 Rules for Posting!!!

RESOURCES: [GMAT MATH BOOK]; 1. Triangles; 2. Polygons; 3. Coordinate Geometry; 4. Factorials; 5. Circles; 6. Number Theory

COLLECTION OF QUESTIONS:
PS: 1. Tough and Tricky questions; 2. Hard questions; 3. Hard questions part 2; 4. Standard deviation; 5. Tough Problem Solving Questions With Solutions; 6. Probability and Combinations Questions With Solutions; 7 Tough and tricky exponents and roots questions; 8 12 Easy Pieces (or not?); 9 Bakers' Dozen; 10 Algebra set. NEW!!!

DS: 1. DS tough questions; 2. DS tough questions part 2; 3. DS tough questions part 3; 4. DS Standard deviation; 5. Inequalities; 6. 700+ GMAT Data Sufficiency Questions With Explanations; 7 Tough and tricky exponents and roots questions; 8 The Discreet Charm of the DS ; 9 Devil's Dozen!!!; 10 Number Properties set. NEW!!!


What are GMAT Club Tests?
25 extra-hard Quant Tests

Find out what's new at GMAT Club - latest features and updates

Re: If 2x^2 –y^2 = 2xy   [#permalink] 29 Dec 2010, 13:33
    Similar topics Author Replies Last post
Similar
Topics:
 New posts if x+y =2 and x^2-xy-10-2y^2=0, what does x-2y equals a)0 cool_jonny009 3 21 Nov 2005, 20:14
New posts What is the value of x^2 + 2xy + y^2? 1) x + y = 7 2) x = 2 john2005 6 18 Apr 2006, 19:13
New posts If x + y = 2, and x^2 - xy - 10 - 2y^2 = 0, what does x - 2y ggarr 3 27 Oct 2006, 16:15
New posts EXPERTS_POSTS_IN_THIS_TOPIC If x+y=2 and x^2 - xy - 10 - 2y^2 = 0, what does x-2y =? vintage83 4 28 Feb 2012, 21:12
New posts 1 Is |x^2| - |y^2| = |x^2–y^2| ? Vamshi8411 2 26 Jul 2012, 05:42
Display posts from previous: Sort by

If 2x^2 –y^2 = 2xy

  Question banks Downloads My Bookmarks Reviews  
Print view
First unread post

Moderators: Bunuel, VeritasPrepKarishma, IanStewart

Search for:


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

Powered by phpBB © phpBB Group and phpBB SEO

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®.

Main navigation

GMAT Resources

Partners

MBA Resources

www.gmac.com|www.mba.com