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

It is currently 25 May 2013, 03:58
Customize  |  Hide

Search
Register
New posts
Unanswered

Solve This!

  Question banks Downloads My Bookmarks Reviews  
  Oldest Best Reply
Search for:
 
Print view
First unread post
Author Message
TAGS:
Senior Manager
Senior Manager
User avatar
Joined: 30 Aug 2003
Posts: 335
Location: BACARDIVILLE
Followers: 1

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

GMAT Tests User
Solve This! [#permalink] New post 26 Jan 2004, 17:44
Solve sqrt(5x^2 - 6x + 8) - sqrt(5x^2 - 6x - 7) = 1
_________________

Pls include reasoning along with all answer posts.
****GMAT Loco****
Este examen me conduce jodiendo loco

Manager
Manager
User avatar
Joined: 26 Dec 2003
Posts: 238
Location: India
Followers: 1

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

GMAT Tests User
 [#permalink] New post 26 Jan 2004, 17:57
Pretty long calculation, uffffffffffff taking - sqrt 5x^2-6x-7 to the otherside and squaring both sides and then after cancelling some terms we get 7=sqrt 5x^2-6x-7 again squaring both sides we get 5x^2-6x-56=0 solve for x we get 4 and -14/5
Senior Manager
Senior Manager
User avatar
Joined: 30 Aug 2003
Posts: 348
Location: dallas , tx
Followers: 1

Kudos [?]: 2 [0], given: 0

GMAT Tests User
 [#permalink] New post 26 Jan 2004, 21:12
It is not clear rakesh..would u mind to show me stepwise..if its not bothering u much.. coz i am getting soemting diff..
_________________

shubhangi

Manager
Manager
User avatar
Joined: 26 Dec 2003
Posts: 238
Location: India
Followers: 1

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

GMAT Tests User
 [#permalink] New post 26 Jan 2004, 21:22
sqrt (5x^2-6x+8) - sqrt (5x^2-6x-7) =1 is the question
taking the term - sqrt(5x^2-6x-7) to other side we get
sqrt (5x^2-6x+8) = 1 + sqrt (5x^2-6x-7)
Now squaring on both sides we get

5x^2-6x+8 = 1 + 5x^2 -6x-7 + 2sqrt(5x^2-6x-7)
we can cancel out 5x^2 and -6x, then we get 14= 2sqrt(5x^2-6x-7)
which means , 7 = sqrt(5x^2-6x-7) , now squaring again we get 49= 5x^2-6x-7, ie 5x^2-6x-56=0 now solve for x
Intern
Intern
Joined: 05 Jan 2004
Posts: 3
Location: VIRGINIA
Followers: 0

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

 [#permalink] New post 30 Jan 2004, 13:50
Let 5x^-6x+8 = A
Therefore sqrtA-sqrt (A+5)=1
squaring both sides:
A+A-15-2*sqrt(A^2-15*A)=1
transferring:
2A-16=2*sqrt(A^2-15*A)
factoring by 2:
A-8=sqrt(A^2-15*A)
squaring again:
=>A^2-16*A+64=A^2-15*A
=>A=64
=>5X^2-6X+8 = 64
=>5X^2-6X-56=0
=>(5X+14)(X-4)=0
=>X= 4, -14/5
  [#permalink] 30 Jan 2004, 13:50
    Similar topics Author Replies Last post
Similar
Topics:
 New posts problem solving lapin 3 10 Aug 2004, 09:42
New posts PS solving mandy 3 05 Jun 2005, 13:09
New posts solving this mand-y 3 03 Jun 2006, 01:34
New posts Problem solving dancer 2 25 Nov 2006, 22:51
New posts solve kaushik04 1 23 Mar 2009, 21:50
Display posts from previous: Sort by

Solve This!

  Question banks Downloads My Bookmarks Reviews  
Print view
First unread post

Moderators: Bunuel, VeritasPrepKarishma

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