Last visit was: 25 Apr 2026, 10:24 It is currently 25 Apr 2026, 10:24
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.
Close
Request Expert Reply
Confirm Cancel
Sub 505 (Easy)|   Algebra|            
User avatar
HKD1710
User avatar
Retired Moderator
Joined: 22 Jun 2014
Last visit: 26 Feb 2021
Posts: 960
Own Kudos:
4,663
 [6]
Given Kudos: 182
Location: India
Concentration: General Management, Technology
GMAT 1: 540 Q45 V20
GPA: 2.49
WE:Information Technology (Computer Software)
GMAT 1: 540 Q45 V20
Posts: 960
Kudos: 4,663
 [6]
1
Kudos
Add Kudos
5
Bookmarks
Bookmark this Post
Most Helpful Reply
User avatar
BrentGMATPrepNow
User avatar
Major Poster
Joined: 12 Sep 2015
Last visit: 31 Oct 2025
Posts: 6,733
Own Kudos:
36,465
 [14]
Given Kudos: 799
Location: Canada
Expert
Expert reply
Posts: 6,733
Kudos: 36,465
 [14]
8
Kudos
Add Kudos
6
Bookmarks
Bookmark this Post
General Discussion
User avatar
dave13
Joined: 09 Mar 2016
Last visit: 15 Mar 2026
Posts: 1,086
Own Kudos:
1,138
 [3]
Given Kudos: 3,851
Posts: 1,086
Kudos: 1,138
 [3]
2
Kudos
Add Kudos
1
Bookmarks
Bookmark this Post
User avatar
ArjunJag1328
Joined: 24 Dec 2017
Last visit: 12 Jan 2025
Posts: 135
Own Kudos:
Given Kudos: 48
Location: India
Concentration: Strategy, Real Estate
Schools: Johnson '21
Schools: Johnson '21
Posts: 135
Kudos: 74
Kudos
Add Kudos
Bookmarks
Bookmark this Post
2 ways to get to the answer.

1. POE (Approximately 1 min and 30 secs to solve it)
2. Find the roots of the equation. (Close to 2 mins)

\(x^2\)-3x+2=0
x=2 or x=1

\(x^2\)-x-2=0
x=2 or x=-1

2 is common in both. Hence IMO E
User avatar
BrentGMATPrepNow
User avatar
Major Poster
Joined: 12 Sep 2015
Last visit: 31 Oct 2025
Posts: 6,733
Own Kudos:
36,465
 [4]
Given Kudos: 799
Location: Canada
Expert
Expert reply
Posts: 6,733
Kudos: 36,465
 [4]
3
Kudos
Add Kudos
Bookmarks
Bookmark this Post
Aside: Finding the roots of each equation, and then identifying the root that the equations have in common will work.
However, this approach COULD be a time killer, if the equations are not so forgiving.

For example: 4x² - 9x - 9 = 0 and 4x² + 19x + 12 = 0

Cheers,
Brent
User avatar
ArjunJag1328
Joined: 24 Dec 2017
Last visit: 12 Jan 2025
Posts: 135
Own Kudos:
74
 [1]
Given Kudos: 48
Location: India
Concentration: Strategy, Real Estate
Schools: Johnson '21
Schools: Johnson '21
Posts: 135
Kudos: 74
 [1]
1
Kudos
Add Kudos
Bookmarks
Bookmark this Post
GMATPrepNow
Aside: Finding the roots of each equation, and then identifying the root that the equations have in common will work.
However, this approach COULD be a time killer, if the equations are not so forgiving.

For example: 4x² - 9x - 9 = 0 and 4x² + 19x + 12 = 0

Cheers,
Brent

So whats the best method?
User avatar
BrentGMATPrepNow
User avatar
Major Poster
Joined: 12 Sep 2015
Last visit: 31 Oct 2025
Posts: 6,733
Own Kudos:
36,465
 [1]
Given Kudos: 799
Location: Canada
Expert
Expert reply
Posts: 6,733
Kudos: 36,465
 [1]
1
Kudos
Add Kudos
Bookmarks
Bookmark this Post
ArjunJag1328
GMATPrepNow
Aside: Finding the roots of each equation, and then identifying the root that the equations have in common will work.
However, this approach COULD be a time killer, if the equations are not so forgiving.

For example: 4x² - 9x - 9 = 0 and 4x² + 19x + 12 = 0

Cheers,
Brent

So whats the best method?

GIVEN: 4x² - 9x - 9 = 0 and 4x² + 19x + 12 = 0
Since both equations are set equal to 0, we can write: 4x² - 9x - 9 = 4x² + 19x + 12
Subtract 4x² from both sides: -9x - 9 = 19x + 12
Subtract 19x from both sides: -28x - 9 = 12
Add 9 to both sides: -28x = 21
Solve: x = -21/28 = -3/4

Cheers,
Brent
User avatar
ArjunJag1328
Joined: 24 Dec 2017
Last visit: 12 Jan 2025
Posts: 135
Own Kudos:
Given Kudos: 48
Location: India
Concentration: Strategy, Real Estate
Schools: Johnson '21
Schools: Johnson '21
Posts: 135
Kudos: 74
Kudos
Add Kudos
Bookmarks
Bookmark this Post
GMATPrepNow
ArjunJag1328
GMATPrepNow
Aside: Finding the roots of each equation, and then identifying the root that the equations have in common will work.
However, this approach COULD be a time killer, if the equations are not so forgiving.

For example: 4x² - 9x - 9 = 0 and 4x² + 19x + 12 = 0

Cheers,
Brent

So whats the best method?

GIVEN: 4x² - 9x - 9 = 0 and 4x² + 19x + 12 = 0
Since both equations are set equal to 0, we can write: 4x² - 9x - 9 = 4x² + 19x + 12
Subtract 4x² from both sides: -9x - 9 = 19x + 12
Subtract 19x from both sides: -28x - 9 = 12
Add 9 to both sides: -28x = 21
Solve: x = -21/28 = -3/4

Cheers,
Brent

=> \(x^2\)-3x+2=\(x^2\)-x-2

=>\(x^2\)-\(x^2\)-3x+x+2+2=0

=>-2x+4=0

=>-2x=-4

=>x=\(\frac{4}{2}\)

=>x=2

Thanks GMATPrepNow
User avatar
bumpbot
User avatar
Non-Human User
Joined: 09 Sep 2013
Last visit: 04 Jan 2021
Posts: 38,985
Own Kudos:
Posts: 38,985
Kudos: 1,117
Kudos
Add Kudos
Bookmarks
Bookmark this Post
Automated notice from GMAT Club BumpBot:

A member just gave Kudos to this thread, showing it’s still useful. I’ve bumped it to the top so more people can benefit. Feel free to add your own questions or solutions.

This post was generated automatically.
Moderators:
Math Expert
109827 posts
Tuck School Moderator
852 posts