Last visit was: 30 Apr 2026, 22:44 It is currently 30 Apr 2026, 22:44
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
Back to Forum
Create Topic
705-805 (Hard)|   Algebra|      
User avatar
Bunuel
User avatar
Math Expert
Joined: 02 Sep 2009
Last visit: 30 Apr 2026
Posts: 109,988
Own Kudos:
812,180
 [3]
Given Kudos: 105,966
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: 109,988
Kudos: 812,180
 [3]
If ab ≠ 0, and (x + a)(x + b) = 0, is x = a ? (1) x − b = 0 (2) a = -b 26 Feb 2021, 01:15
Kudos
Add Kudos
3
Bookmarks
Bookmark this Post
00:00
Start Timer
Pause Timer
Resume Timer
Show Answer
Hide
Show
History
A
Be sure to select an answer first to save it in the Error Log before revealing the correct answer (OA)!

Difficulty:

75% (hard)

Question Stats:

47% (01:48) correct 53% (01:56) wrong based on 94 sessions

History

Date
Time
Result
Not Attempted Yet
If ab ≠ 0, and (x + a)(x + b) = 0, is x = a ?

(1) x − b = 0

(2) a = −b


Project DS Butler Data Sufficiency (DS3)


For DS butler Questions Click Here
ShowHide Answer
Official Answer
A
User avatar
GMATinsight
User avatar
Major Poster
Joined: 08 Jul 2010
Last visit: 30 Apr 2026
Posts: 6,991
Own Kudos:
16,942
 [2]
Given Kudos: 128
Status:GMAT/GRE Tutor l Admission Consultant l On-Demand Course creator
Location: India
GMAT: QUANT+DI EXPERT
Schools: IIM (A) ISB '24
GMAT 1: 750 Q51 V41
WE:Education (Education)
Products:
My Reviews
Expert
Expert reply
Schools: IIM (A) ISB '24
GMAT 1: 750 Q51 V41
Posts: 6,991
Kudos: 16,942
 [2]
If ab ≠ 0, and (x + a)(x + b) = 0, is x = a ? (1) x − b = 0 (2) a = -b 26 Feb 2021, 01:25
2
Kudos
Add Kudos
Bookmarks
Bookmark this Post
Bunuel
If ab ≠ 0, and (x + a)(x + b) = 0, is x = a ?

(1) x − b = 0

(2) a = −b
Show more

Given: x = -a or -b

Question: Is x = a?

Statement 1: x − b = 0
i.e. x = b
i.e. x ≠ -b i.e. x = -a

SUFFICIENT

Statement 2: a = −b

i.e. if x = -a, then x = b NO
i.e. if x = -b, then x = a YES

i..e. Both conditions are possible hence

NOT SUFFICIENT

Answer: Option A
avatar
GCMEMBER
avatar
Joined: 09 Dec 2019
Last visit: 03 Jun 2021
Posts: 123
Own Kudos:
176
 [1]
Given Kudos: 5
Posts: 123
Kudos: 176
 [1]
If ab ≠ 0, and (x + a)(x + b) = 0, is x = a ? (1) x − b = 0 (2) a = -b 26 Feb 2021, 20:28
1
Kudos
Add Kudos
Bookmarks
Bookmark this Post
If ab ≠ 0, and (x + a)(x + b) = 0, is x = a ?

(1) x − b = 0
x = b
(x + a)(x + b) = 0
(x + a)(b + b) = 0
(x + a) = 0
x = -a
Sufficient

2) a = −b
(x + a)(x + b) = 0
(x + a)(x - a) = 0
x = a or -a
Not sufficient

Option A

Posted from my mobile device
avatar
TarunKumar1234
avatar
Joined: 14 Jul 2020
Last visit: 28 Feb 2024
Posts: 1,102
Own Kudos:
1,358
 [1]
Given Kudos: 351
Location: India
Posts: 1,102
Kudos: 1,358
 [1]
If ab ≠ 0, and (x + a)(x + b) = 0, is x = a ? (1) x − b = 0 (2) a = -b 27 Feb 2021, 01:06
1
Kudos
Add Kudos
Bookmarks
Bookmark this Post
If ab ≠ 0, and (x + a)(x + b) = 0, is x = a ?

Stat1: x − b = 0, then, (x +a)*2b = 0 or, x = -a. Sufficient.

Stat2: a = −b, we don't know any relationship with x. Not Sufficient.

So, I think A. :)
User avatar
HoneyLemon
User avatar
Stern School Moderator
Joined: 26 May 2020
Last visit: 02 Oct 2023
Posts: 627
Own Kudos:
571
 [1]
Given Kudos: 219
Status:Spirited
Concentration: General Management, Technology
Schools: Stern '23 LBS '23 Said '23 IIMB EPGP'22 INSEAD Jan'23 intake
WE:Analyst (Computer Software)
Schools: Stern '23 LBS '23 Said '23 IIMB EPGP'22 INSEAD Jan'23 intake
Posts: 627
Kudos: 571
 [1]
If ab ≠ 0, and (x + a)(x + b) = 0, is x = a ? (1) x − b = 0 (2) a = -b 27 Feb 2021, 05:34
1
Kudos
Add Kudos
Bookmarks
Bookmark this Post
Bunuel
If ab ≠ 0, and (x + a)(x + b) = 0, is x = a ?

(1) x − b = 0

(2) a = −b
Show more
imo A
If ab ≠ 0, and (x + a)(x + b) = 0, is x = a ?

(1) x − b = 0

=> x=b . So X = -a . Hence is x = a ? => Ans is No .
St 1 is Sufficient .

(2) a = −b
Hence
(x + a)(x -a) = 0
=> x^2 = a^2
=> x = +- a , is x = a ? .. The ans is both Yes and No .
St 2 is NOt Sufficient .


Hence Ans is A
User avatar
EgmatQuantExpert
User avatar
e-GMAT Representative
Joined: 04 Jan 2015
Last visit: 02 Apr 2024
Posts: 3,657
Own Kudos:
20,911
 [1]
Given Kudos: 165
Expert
Expert reply
Posts: 3,657
Kudos: 20,911
 [1]
If ab ≠ 0, and (x + a)(x + b) = 0, is x = a ? (1) x − b = 0 (2) a = -b 28 Feb 2021, 03:11
1
Kudos
Add Kudos
Bookmarks
Bookmark this Post

Solution



Given
     ab ≠ 0
     (x + a)(x + b) = 0

To find
We need to determine
    • whether x = a

Approach and Working out

    • Question Statement Analysis
      o ab ≠ 0
         a ≠ 0
         b ≠ 0
      o (x + a)(x + b) = 0
         x + a = 0 or x + b = 0
         x = -a or x = -b --------(1)

    • Statement 1
      o x – b = 0
         x = b --------(2)
      • So, x ≠ -b. -------(3)
        o Since, if x= -b as well, then from (2), b = -b, which means b = 0. (Impossible)
      • From (1) and (3), x = -a.
        o Again, this means that x ≠ a, since a ≠ 0.
        o So, we get a sure NO.
        o Statement 1 is sufficient alone.

    • Statement 2
      o a = -b --------(3)
         From question statement, we have x = -a or x = -b.

      • Case 1: If x = -a, then from (3), we get x = b.
        o Now, if x = -a, it cannot be equal to a as well.
           Since -a ≠ a (since a ≠ 0)
        o So, we get NO from this case.

      • Case 2: If x = -b, then from (3), we get x = a.
        o So, we get YES from this case.
        o Statement 2 is insufficient alone.

Thus, option A is the correct answer.
Correct Answer: Option A
User avatar
bumpbot
User avatar
Non-Human User
Joined: 09 Sep 2013
Last visit: 04 Jan 2021
Posts: 39,011
Own Kudos:
1,122
Posts: 39,011
Kudos: 1,122
If ab ≠ 0, and (x + a)(x + b) = 0, is x = a ? (1) x − b = 0 (2) a = -b 04 Oct 2023, 12:08
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:
Bunuel
Math Expert
109988 posts
kingbucky
498 posts
Gmat860sanskar
212 posts