Live GMAT classes with Target Test Prep start Nov 21 and Nov 22. First class free.

See classes
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.

Newsweek Readers’ Choice Awards 2026 winner: Target Test Prep, #1 Test Prep

Target Test Prep was voted #1 Best Test Prep in the 2026 Newsweek Readers’ Choice™ Awards.

★★★★★5.0563 reviews
GMATLiveTeachStarts Nov 22
Josh Braslow, Target Test Prep GMAT expert
LIVE ONLINE CLASSES

Get Ready for GMAT Test Day Faster with Live Online Classes

with Josh Braslow, 20+ years in test prep

Nov 22 · Josh Braslow
Sun · 9:30 AM to 12:30 PM ET
Included
40 hours of live online classes + 6 months of TTP OnDemand
  • Attend the first class for free
  • Every class is recorded, so you never fall behind
View classes & enroll
Limited seats availableTarget Test Prep
EALiveTeachOnDemandStart anytime
EXECUTIVE ASSESSMENT

Target Test Prep EA OnDemand

Self-paced EA prep. Study on your schedule.

EXECUTIVE ASSESSMENT

with

165+ EA score guarantee
$05-day trial no automatic billing
Schedule
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 Start free 5-day trial
Limited cohort · enrollment openTrial includes full course accessTarget Test Prep
GMATOnDemandStart 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 563 reviewsTarget Test Prep

No solution N

Expert replies
Post new topic Post Reply
Subscribe topic
Previous Topic Next Topic
Senior | Next Rank: 100 Posts
Posts: 38
Joined: Tue Nov 15, 2011 3:28 pm
Thanked: 1 times
by mysseo » Mon Dec 19, 2011 6:02 pm
Each of the following equations has at least one solution EXCEPT
A. –2^n = (–2)^-n
B. 2^-n = (–2)^n
C. 2^n = (–2)^-n
D. (–2)^n = –2^n
E. (–2)^-n = –2^-n


It was on Manhattan CAT. Parenthesis makes me confused.
Top
Join the discussion
Source: — Problem Solving |
User avatar
GMAT Instructor
Posts: 349
Joined: Wed Sep 28, 2011 3:38 pmFollowed by: 54 members
Location: Austin, TX
Thanked: 236 times
GMAT Score:770

by GmatMathPro » Mon Dec 19, 2011 6:12 pm
mysseo wrote:Each of the following equations has at least one solution EXCEPT
A. –2^n = (–2)^-n
B. 2^-n = (–2)^n
C. 2^n = (–2)^-n
D. (–2)^n = –2^n
E. (–2)^-n = –2^-n


It was on Manhattan CAT. I am not sure how to solve it.
I would start by plugging simple values for n into the equations. Anything (except zero) to the zero power is one, so that would be the simplest place to start. Note that n=0 is a solution for B & C. Now try n=1. n=1 is a solution to D & E. Therefore, the correct answer is A.
Last edited by GmatMathPro on Mon Dec 19, 2011 6:36 pm, edited 1 time in total.
Pete Ackley
GMAT Math Pro
Free Online Tutoring Trial
Top
Join the discussion
Senior | Next Rank: 100 Posts
Posts: 38
Joined: Tue Nov 15, 2011 3:28 pm
Thanked: 1 times

by mysseo » Mon Dec 19, 2011 6:32 pm
Why isn't A's solution n=0? -2^0=0, (-2)^-0=0.
Top
Join the discussion
User avatar
GMAT Instructor
Posts: 349
Joined: Wed Sep 28, 2011 3:38 pmFollowed by: 54 members
Location: Austin, TX
Thanked: 236 times
GMAT Score:770

by GmatMathPro » Mon Dec 19, 2011 6:35 pm
mysseo wrote:Why isn't A's solution n=0? -2^0=0, (-2)^-0=0.
Remember that anything (except zero) to the zero power is one, not zero, so -2^0=-1 and (-2)^-0=1.
Pete Ackley
GMAT Math Pro
Free Online Tutoring Trial
Top
Join the discussion
Senior | Next Rank: 100 Posts
Posts: 38
Joined: Tue Nov 15, 2011 3:28 pm
Thanked: 1 times

by mysseo » Mon Dec 19, 2011 6:43 pm
I got it. Thank you so much for your help.
Top
Join the discussion