Last visit was: 30 Apr 2026, 15:20 It is currently 30 Apr 2026, 15:20
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
Sub 505 (Easy)|   Algebra|            
User avatar
HasnainAfxal
User avatar
Joined: 06 Sep 2018
Last visit: 12 Mar 2022
Posts: 125
Own Kudos:
65
 [9]
Given Kudos: 72
Location: Pakistan
Concentration: Finance, Operations
GPA: 2.87
WE:Engineering (Other)
Products:
My Reviews
Posts: 125
Kudos: 65
 [9]
If a = 7 and b = -7, what is the value of 2a - 2b + b^2 ? 08 Sep 2018, 10:25
1
Kudos
Add Kudos
8
Bookmarks
Bookmark this Post
00:00
Start Timer
Pause Timer
Resume Timer
Show Answer
Hide
Show
History
E
Be sure to select an answer first to save it in the Error Log before revealing the correct answer (OA)!

Difficulty:

5% (low)

Question Stats:

93% (00:34) correct 7% (00:34) wrong based on 1512 sessions

History

Date
Time
Result
Not Attempted Yet
If \(a = 7\) and \(b = -7\), what is the value of \(2a - 2b + b^2\) ?

(A) -49
(B) 21
(C) 49
(D) 63
(E) 77
ShowHide Answer
Official Answer
E
If this question felt shaky, try an adaptive mini quiz of similar problems in GMAT Club Forum Quiz →. Free plan gives 5 questions per day.
User avatar
souvonik2k
User avatar
Retired Moderator
Joined: 25 Nov 2015
Last visit: 05 Dec 2021
Posts: 949
Own Kudos:
2,251
Given Kudos: 751
Status:Preparing for GMAT
Location: India
GPA: 3.64
Products:
My Reviews
Posts: 949
Kudos: 2,251
If a = 7 and b = -7, what is the value of 2a - 2b + b^2 ? 08 Sep 2018, 10:31
Kudos
Add Kudos
Bookmarks
Bookmark this Post
Hasnain786
If \(a = 7\) and\(b = -7\), what is the value of \(2a - 2b + b^2\) ?

(A) -49
(B) 21
(C) 49
(D) 63
(E) 77
Show more

a=7, b=-7
\(2a - 2b + b^2\) = 2x7-2x(-7)+(-7)^2 = 14+14+49 = 77
Answer E.
User avatar
Abhishek009
User avatar
Board of Directors
Joined: 11 Jun 2011
Last visit: 17 Dec 2025
Posts: 5,902
Own Kudos:
5,459
 [1]
Given Kudos: 463
Status:QA & VA Forum Moderator
Location: India
GPA: 3.5
WE:Business Development (Commercial Banking)
Posts: 5,902
Kudos: 5,459
 [1]
If a = 7 and b = -7, what is the value of 2a - 2b + b^2 ? 08 Sep 2018, 11:15
1
Kudos
Add Kudos
Bookmarks
Bookmark this Post
Hasnain786
If \(a = 7\) and\(b = -7\), what is the value of \(2a - 2b + b^2\) ?

(A) -49
(B) 21
(C) 49
(D) 63
(E) 77
Show more

\(2a - 2b + b^2\)

\(= 2a - b ( 2 - b)\)

\(= 2*7 + 7 ( 2 + 7)\)

\(= 14 + 7 *9\)

\(= 14 + 63\)

\(= 77\), Answer must be (E)
User avatar
Kinshook
User avatar
Major Poster
Joined: 03 Jun 2019
Last visit: 30 Apr 2026
Posts: 5,990
Own Kudos:
5,864
Given Kudos: 163
Location: India
Schools: HBS '26 CBS '26 Wharton '26
GMAT 1: 690 Q50 V34
WE:Engineering (Transportation)
Products:
My Reviews
Schools: HBS '26 CBS '26 Wharton '26
GMAT 1: 690 Q50 V34
Posts: 5,990
Kudos: 5,864
If a = 7 and b = -7, what is the value of 2a - 2b + b^2 ? 15 Sep 2019, 07:02
Kudos
Add Kudos
Bookmarks
Bookmark this Post
HasnainAfxal
If \(a = 7\) and \(b = -7\), what is the value of \(2a - 2b + b^2\) ?

(A) -49
(B) 21
(C) 49
(D) 63
(E) 77
Show more

Given: \(a = 7\) and \(b = -7\)

Asked: What is the value of \(2a - 2b + b^2\) ?

2(7) - 2(-7) + (-7)^2
= 14 + 14 + 49 = 77

IMO E
User avatar
CrackverbalGMAT
User avatar
Major Poster
Joined: 03 Oct 2013
Last visit: 30 Apr 2026
Posts: 4,846
Own Kudos:
9,188
Given Kudos: 226
Affiliations: CrackVerbal
Location: India
Expert
Expert reply
Posts: 4,846
Kudos: 9,188
If a = 7 and b = -7, what is the value of 2a - 2b + b^2 ? 26 Aug 2020, 09:19
Kudos
Add Kudos
Bookmarks
Bookmark this Post
The question is easy enough, and substituting the values would be sufficient and the best way in this case to get to the answer.

If there were more terms or if the values were so big that substitution would involve too much calculation, then we might try to get to the answer by eliminating options.


(a) The first elimination point could be to see if \(2a - 2b + b^2\) is Odd or Even. In this case since all the options are Odd, we do not need to check the same.



(b) We know that 2a is positive, -2b is also positiveve (since b = -7) and \(b^2\) will always be positive.

\(2a - 2b + b^2\) is positiveve and hence Option A is ruled out.



(c) Since 2(a - b) = 2(a - b) is positive and \(b^2\) = 49, Options B and C are eliminated (as they have to be greater than 49.



(d) a - b = 7 - (-7) = 14 and 14 + 49 = 63. Option D gets ruled without having to multiply by 2 as the answer has to be greater than 63.


Option E would be the correct choice.

Arun Kumar
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 a = 7 and b = -7, what is the value of 2a - 2b + b^2 ? 25 Jul 2025, 10:04
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
110017 posts
Krunaal
Tuck School Moderator
852 posts