Quadratic Equation Help!! : GMAT Quantitative Section
Check GMAT Club Decision Tracker for the Latest School Decision Releases https://gmatclub.com/AppTrack

 It is currently 22 Feb 2017, 22:22

### 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

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

# Quadratic Equation Help!!

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

### Hide Tags

Intern
Joined: 28 Feb 2011
Posts: 35
Followers: 0

Kudos [?]: 7 [0], given: 1

### Show Tags

06 May 2011, 18:27
Hi Guys,

I came across the below problem in a gmat online practice test..can anybody pls provide
suggestions to solve the problem?

If a+b+2ac =0 are the roots of the equation ax^2 +bx +c = 0 then which of the following is true?

a+b+2ac = 0
a^2+b^2+2ac=0
a-b+2ac =0
a^2-b^2+2ac = 0
none of these

My approach is :

formula for finding roots of a quadratic equation is -b +/- SQRT(b^2-4ac)/2a

a+b+2ac = -b +/- SQRT(b^2-4ac)/2a

a+2ac +b = -b +/- SQRT(b^2-4ac)/2a

a(1+2c) +b = -b +/- SQRT(b^2-4ac)/2a combining like terms on the left hand side eq.

squaring on both sides:

(a(1+2c) +b)^2 = b^2+/- b^2-4ac/4a^2

getting too long here..any suggestions pls?

Anu
Senior Manager
Joined: 24 Mar 2011
Posts: 457
Location: Texas
Followers: 5

Kudos [?]: 171 [0], given: 20

### Show Tags

06 May 2011, 21:50
anuu wrote:
If a+b+2ac =0 are the roots of the equation ax^2 +bx +c = 0 then which of the following is true?

Anu

did not understand the highlighted portion... is it possible to have a+b+2ac=0 as roots?
Intern
Joined: 28 Feb 2011
Posts: 35
Followers: 0

Kudos [?]: 7 [0], given: 1

### Show Tags

07 May 2011, 07:50
I too had the same thought on whetther a+b+2ac (that too with 3 variables) could be the roots...but this os how the question was mentioned in the online practice test.

Is this a typo in the question ?

Anuu
Re: Quadratic Equation Help!!   [#permalink] 07 May 2011, 07:50
Similar topics Replies Last post
Similar
Topics:
Quadratic equations 2 09 Jun 2016, 23:00
6 Quadratic equations in DS problems 6 19 Nov 2011, 06:05
solving quadratic equations 3 08 Jun 2011, 14:15
Quadratic Equation Help Required 7 06 May 2011, 11:47
3 Equating coefficients in a quadratic equation 5 29 Oct 2010, 05:30
Display posts from previous: Sort by

# Quadratic Equation Help!!

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

 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®.