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

Redeem

Target Test Prep · GMAT

Choose how you want to prepare

Learn live with an expert or move at your own pace. Every option includes the complete TTP study system.

★★★★★5.0559 reviews
Vote for Target Test Prep, Newsweek Readers’ Choice Awards 2026
NEWSWEEK READERS’ CHOICE 2026

BIG NEWS! Target Test Prep has been nominated, and they’d love your vote!

TTP has worked incredibly hard to build the best test prep experience possible, and winning Newsweek’s 2026 Readers’ Choice Award for Best Test Prep would mean a lot to them. If TTP has helped you, they’d be incredibly grateful for your vote. You can vote once each day through September 9.

Vote for TTP
GMATLiveTeach 7 seats left
Chris Peckover
NEXT LIVE COHORT

Oct 13 to Jan 7, 2027

with Chris Peckover

Schedule
Tue, Thu · 8:00 to 10:00 PM ET
Included
40 live hours + 6 months of GMAT OnDemand
  • Live instruction and real-time questions
  • Class recordings and assigned practice
View class & enroll
Limited cohort · enrollment openTarget Test Prep
EALiveTeach 5 seats left
Logan Thompson
EXECUTIVE ASSESSMENT

Sep 6 to Dec 6, 2026

with Logan Thompson

Schedule
Sun · 9:30 AM to 12:30 PM ET
Included
40 hours of live online classes plus six months of access to the complete TTP EA OnDemand course.
  • 165+ EA Score Guarantee
  • 4,100+ Quant, Verbal, and Integrated Reasoning practice questions
  • 400+ hours of in-depth video lessons
  • 3,000+ step-by-step video solutions
View EA class & enroll
Limited cohort · enrollment openTarget Test Prep
GMATOnDemand Start anytime
SELF-PACED MASTERCLASS

Target Test Prep GMAT OnDemand

Complete access from day one. Study on your schedule.

715+ score guarantee
$0to start then $127/mo
  • Personalized study plan and analytics
  • Thousands of lessons and practice questions
Start free 5-day trial
Read 559 reviewsTarget Test Prep

Compare the format, schedule, and included access before enrolling. Prices and seat counts shown reflect the supplied offer details.

quadratic eqn

Expert replies
Post new topic Post Reply
Previous Topic Next Topic
Source: — Data Sufficiency |
User avatar
Community Manager
Posts: 1537
Joined: Mon Aug 10, 2009 6:10 pmFollowed by: 252 members
Thanked: 653 times

by papgust » Mon Feb 08, 2010 5:49 am
I would go for D

A. d = 3

x^2 + bx + c = (x + 3)^2 = x^2 + 6x + 9.

c=9. Sufficient.

B. b = 6

x^2 + 6x + c = (x + d)^2

x^2 + 6x + c = x^2 + 2dx + d^2

2d = 6
d = 3

c = d^2 = 3^2 = 9
Sufficient.
Top
Join the discussion
Log in to postLogin with Googleuse password
QUOTE IN REPLY
User avatar
Legendary Member
Posts: 1560
Joined: Tue Nov 17, 2009 2:38 amFollowed by: 5 members
Thanked: 137 times

by thephoenix » Mon Feb 08, 2010 10:51 am
IMO D
for DS in GMAT many a time a trick is hidden in the q itself
here for all values of X signifies x can be zero
in that case
x^2+bx+c=(x+d)^2--->c=d^2

s1) d=3--->c=d^2=9
suff

s2) b=6--->2d=6(when (x+d)^2 is expanded=x^2+2dx+d^2--->d=3--->c=9
suff
Top
Join the discussion
Log in to postLogin with Googleuse password
QUOTE IN REPLY
User avatar
Legendary Member
Posts: 1022
Joined: Mon Jul 20, 2009 11:49 pmFollowed by: 2 members
Location: Gandhinagar
Thanked: 41 times

by shashank.ism » Mon Feb 08, 2010 8:17 pm
gmatnmein2010 wrote:If b, c, and d are constants and x^2 + bx + c = (x + d)^2 for all values of x, what is the value of c?
(1) d = 3
(2) b = 6
X^2 +bx+c = (x+d)^2 --> bx+c = 2dx+d^2 --> (2d-b)X= 4d^2 - c this is true for all values of X
so if we put X=0, c= d^2
S1: D=3 so c= d^2 = 3^2=9. sufficient.
S2: if b= 6 , x^2 + 6x + c = x^2 + 2dx + d^2 --> so 2d=6 --> d=3 --> c=d^2 =9...............sufficient


I would go with D
My Websites:
www.mba.webmaggu.com - India's social Network for MBA Aspirants

www.deal.webmaggu.com -India's online discount, coupon, free stuff informer.

www.dictionary.webmaggu.com - A compact free online dictionary with images.

Nothing is Impossible, even Impossible says I'm possible.
Top
Join the discussion
Log in to postLogin with Googleuse password
QUOTE IN REPLY
User avatar
Legendary Member
Posts: 1275
Joined: Thu Sep 21, 2006 11:13 pmFollowed by: 2 members
Location: Arabian Sea
Thanked: 125 times

by ajith » Tue Feb 09, 2010 2:59 am
gmatnmein2010 wrote:If b, c, and d are constants and x^2 + bx + c = (x + d)^2 for all values of x, what is the value of c?
(1) d = 3
(2) b = 6
x^2 + bx + c = (x + d)^2 =x^2 + 2d + d^2

Comparing coefficients on both sides

b =2d
c= d^2

1.) d =3 ; c = d^2 = 9 sufficient
2) b =6; d =3 ; c = d^2 = 9; sufficient

D
Always borrow money from a pessimist, he doesn't expect to be paid back.
Top
Join the discussion
Log in to postLogin with Googleuse password
QUOTE IN REPLY
Post new topic Post Reply
• Page 1 of 1