BREAKING: Target Test Prep releases Brand New 2026 On Demand GMAT prep course

Redeem

equal in magnitude but opposite in sign

This topic has expert replies
Post new topic Post Reply
Previous Topic Next Topic
User avatar
GMAT Instructor
Posts: 3650
Joined: Wed Jan 21, 2009 4:27 am
Location: India
Thanked: 267 times
Followed by:80 members
GMAT Score:760

equal in magnitude but opposite in sign

by sanju09 » Sat Jul 31, 2010 5:53 am
Which of the following equations has roots that are equal in magnitude but opposite in sign to the roots of the equation x^2 + 5 x + 6 = 0?
A. x^2 + 6 x - 5 = 0
B. x^2 + 5 x - 6 = 0
C. x^2 + 6 x + 5 = 0
D. x^2 - 5 x + 6 = 0
E. x^2 - 5 x - 6 = 0

[spoiler]Source: winningprep.com[/spoiler]
The mind is everything. What you think you become. -Lord Buddha



Sanjeev K Saxena
Quantitative Instructor
The Princeton Review - Manya Abroad
Lucknow-226001

www.manyagroup.com
Top
Source: — Problem Solving |
User avatar
Legendary Member
Posts: 748
Joined: Sun Jan 31, 2010 7:54 am
Thanked: 46 times
Followed by:3 members

by outreach » Sat Jul 31, 2010 8:12 am
roots of x^2 + 5 x + 6 = 0 are -2 and -3
D
roots of x^2 - 5 x + 6 = 0 are 2 and 3
sanju09 wrote:Which of the following equations has roots that are equal in magnitude but opposite in sign to the roots of the equation x^2 + 5 x + 6 = 0?
A. x^2 + 6 x - 5 = 0
B. x^2 + 5 x - 6 = 0
C. x^2 + 6 x + 5 = 0
D. x^2 - 5 x + 6 = 0
E. x^2 - 5 x - 6 = 0

[spoiler]Source: winningprep.com[/spoiler]
-------------------------------------
--------------------------------------
General blog
https://amarnaik.wordpress.com
MBA blog
https://amarrnaik.blocked/
Top

GMAT/MBA Expert

User avatar
GMAT Instructor
Posts: 16207
Joined: Mon Dec 08, 2008 6:26 pm
Location: Vancouver, BC
Thanked: 5254 times
Followed by:1268 members
GMAT Score:770

by Brent@GMATPrepNow » Sat Jul 31, 2010 8:13 am
sanju09 wrote:Which of the following equations has roots that are equal in magnitude but opposite in sign to the roots of the equation x^2 + 5 x + 6 = 0?
A. x^2 + 6 x - 5 = 0
B. x^2 + 5 x - 6 = 0
C. x^2 + 6 x + 5 = 0
D. x^2 - 5 x + 6 = 0
E. x^2 - 5 x - 6 = 0
[spoiler]Source: winningprep.com[/spoiler]
First we'll solve x^2 + 5 x + 6 = 0 by factoring the left hand side.
(x+2)(x+3)=0 --> x= -2 and = -3

So, we want a new equation such that the roots are 2 and 3
Well the equation (x-2)(x-3)=0 will have roots 2 and 3
When we expand we get x^2 - 5x + 6 = 0
Answer=D
Brent Hanneson - Creator of GMATPrepNow.com
Image
Top
Post new topic Post Reply
• Page 1 of 1