Last visit was: 23 Apr 2026, 02:41 It is currently 23 Apr 2026, 02:41
Home
Messages
Tests
Schools
Events
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.
Go to My Error Log Learn more
Close
Request Expert Reply
Confirm Cancel
User avatar
greatchap
User avatar
Joined: 14 May 2007
Last visit: 23 Aug 2018
Posts: 128
Own Kudos:
355
Given Kudos: 12
Location: India
Posts: 128
Kudos: 355
Number system problem 12 Sep 2010, 07:56
Kudos
Add Kudos
Bookmarks
Bookmark this Post
00:00
Start Timer
Pause Timer
Resume Timer
Show Answer
Hide
Show
History
N
Be sure to select an answer first to save it in the Error Log before revealing the correct answer (OA)!

Difficulty:

(N/A)

Question Stats:

80% (00:18) correct 20% (01:13) wrong based on 6 sessions

History

Date
Time
Result
Not Attempted Yet
Hi Guys,

How can I solve the following question ?

Q-1) If a is the solution of the equation x^2 - 4 = 0 and B is the solution set of the equation x^2 - 3x + 2=0, how many elements are in the union of the two sets.

OA is : 3

I am unable to solve B.

Please advice.

Thanks,

Cheers,
GR



Archived Topic
Hi there,
This topic has been closed and archived due to inactivity or violation of community quality standards. No more replies are possible here.
Where to now? Join ongoing discussions on thousands of quality questions in our Problem Solving (PS) Forum
Still interested in this question? Check out the "Best Topics" block below for a better discussion on this exact question, as well as several more related questions.
Thank you for understanding, and happy exploring!
User avatar
saxenashobhit
User avatar
Joined: 20 Jul 2010
Last visit: 14 Nov 2013
Posts: 135
Own Kudos:
256
 [2]
Given Kudos: 9
Products:
My Reviews
Posts: 135
Kudos: 256
 [2]
Number system problem 12 Sep 2010, 09:02
2
Kudos
Add Kudos
Bookmarks
Bookmark this Post
From equation 1 x=2, x=-2

From equation 2; x=2 and x=1

So union has 3 solutions

How to solve B
\(x^2\)-2x-x+2=0
So (x-2)(x-1)=0
User avatar
greatchap
User avatar
Joined: 14 May 2007
Last visit: 23 Aug 2018
Posts: 128
Own Kudos:
355
Given Kudos: 12
Location: India
Posts: 128
Kudos: 355
Number system problem 12 Sep 2010, 09:38
Kudos
Add Kudos
Bookmarks
Bookmark this Post
saxenashobhit
From equation 1 x=2, x=-2

From equation 2; x=2 and x=1

So union has 3 solutions

How to solve B
\(x^2\)-2x-x+2=0
So (x-2)(x-1)=0
Show more

How do we convert \(x^2\)-2x-x+2=0 to (x-2)(x-1)=0 ?
little rusty with algebra.
User avatar
shaselai
User avatar
Current Student
Joined: 12 Jun 2009
Last visit: 17 Jun 2019
Posts: 1,673
Own Kudos:
405
Given Kudos: 52
Status:What's your raashee?
Location: United States (NC)
Concentration: Strategy, Finance
Schools: UNC (Kenan-Flagler) - Class of 2013
GMAT 1: 720 Q49 V39
WE:Programming (Computer Software)
Products:
My Reviews
Schools: UNC (Kenan-Flagler) - Class of 2013
GMAT 1: 720 Q49 V39
Posts: 1,673
Kudos: 405
Number system problem 12 Sep 2010, 10:20
Kudos
Add Kudos
Bookmarks
Bookmark this Post
greatchap
saxenashobhit
From equation 1 x=2, x=-2

From equation 2; x=2 and x=1

So union has 3 solutions

How to solve B
\(x^2\)-2x-x+2=0
So (x-2)(x-1)=0

How do we convert \(x^2\)-2x-x+2=0 to (x-2)(x-1)=0 ?
little rusty with algebra.
Show more


(x-2)(x-1) so lets FOIL.
x*x + x(-1) + (-2 *x) + (-2*-1) = x^2 -x -2x +2 = x^2 -3x +2
User avatar
Bunuel
User avatar
Math Expert
Joined: 02 Sep 2009
Last visit: 23 Apr 2026
Posts: 109,763
Own Kudos:
810,727
Given Kudos: 105,850
Products:
GMAT Club Tests Forum Quiz
Expert
Expert reply
Active GMAT Club Expert! Tag them with @ followed by their username for a faster response.
Posts: 109,763
Kudos: 810,727
Number system problem 12 Sep 2010, 11:06
Kudos
Add Kudos
Bookmarks
Bookmark this Post
greatchap
Hi Guys,

How can I solve the following question ?

Q-1) If a is the solution of the equation x^2 - 4 = 0 and B is the solution set of the equation x^2 - 3x + 2=0, how many elements are in the union of the two sets.

OA is : 3

I am unable to solve B.

Please advice.

Thanks,

Cheers,
GR
Show more

Seems that you need to brush up on quadratics.

Solving Quadratic Equations: https://www.purplemath.com/modules/solvquad.htm

Factoring Quadratics: https://www.purplemath.com/modules/factquad.htm

Good links with several different approaches.

Hope it helps.
User avatar
greatchap
User avatar
Joined: 14 May 2007
Last visit: 23 Aug 2018
Posts: 128
Own Kudos:
355
Given Kudos: 12
Location: India
Posts: 128
Kudos: 355
Number system problem Updated on: 13 Sep 2010, 08:46
Originally posted by greatchap on 13 Sep 2010, 08:42.
Last edited by greatchap on 13 Sep 2010, 08:46, edited 1 time in total.
Kudos
Add Kudos
Bookmarks
Bookmark this Post
shaselai
greatchap
saxenashobhit
From equation 1 x=2, x=-2

From equation 2; x=2 and x=1

So union has 3 solutions

How to solve B
\(x^2\)-2x-x+2=0
So (x-2)(x-1)=0

How do we convert \(x^2\)-2x-x+2=0 to (x-2)(x-1)=0 ?
little rusty with algebra.


(x-2)(x-1) so lets FOIL.
x*x + x(-1) + (-2 *x) + (-2*-1) = x^2 -x -2x +2 = x^2 -3x +2
Show more

Dude, I know how to solve (X-2) (x-1). I wanted to know how to convert \(x^2\)-2x-x+2=0 to (x-2)(x-1)

Now i know, read content on factoring.
User avatar
greatchap
User avatar
Joined: 14 May 2007
Last visit: 23 Aug 2018
Posts: 128
Own Kudos:
355
Given Kudos: 12
Location: India
Posts: 128
Kudos: 355
Number system problem 13 Sep 2010, 08:44
Kudos
Add Kudos
Bookmarks
Bookmark this Post
Thanks Bunuel for help on algebra.



Archived Topic
Hi there,
This topic has been closed and archived due to inactivity or violation of community quality standards. No more replies are possible here.
Where to now? Join ongoing discussions on thousands of quality questions in our Problem Solving (PS) Forum
Still interested in this question? Check out the "Best Topics" block above for a better discussion on this exact question, as well as several more related questions.
Thank you for understanding, and happy exploring!
Moderator:
Bunuel
Math Expert
109763 posts