x^n = x^(n+2)
x^n = x^n * x^2
x^2 = 1
x= -1 or +1
Statement (1)
if x=-1
x = x^2-2
x= 1-2 = -1.
x=1
x = 1-2 = -1
Sufficient.
Statement (2)
2x < x^5
x=-1
-2 < -1, x negative.
x=1
2 < 1, this case cannot exist. Sufficient.
Thus, D.
OA?
BREAKING: Target Test Prep releases Brand New 2026 On Demand GMAT prep course
Redeem
Featured Course
Target Test Prep GMAT OnDemand
Scott Woodbury-Stewart’s private virtual classroom — 400 hours of master-class video lessons for the GMAT Focus Edition.
- 715+ score guarantee — highest in the industry (99th percentile)
- 52 chapters · 1,500+ lessons · 4,000+ practice questions
- 400 hours of video · 1,500+ instructor-led HD smartboard lessons
- 300,000+ students accepted to Harvard, Stanford, Wharton, Booth & Sloan & more
- 24/7 live support + weekly Zoom office hours with GMAT instructors
- TTP AI Assist — 24/7 AI-powered virtual tutor for instant help
- 1,200+ flashcards + AI-powered study assistant & daily calendar
- OnDemand, LiveTeach & GMAT Bootcamp formats available
- Also: GRE, SAT Math & Executive Assessment courses
- MBA Admissions Consulting now available
- 🏆 2025 EdTech Breakthrough Award: Test Prep Solution Provider of the Year
- 200,000+ students served
- 5-day free trial — $0 to start, no auto-billing, cancel anytime
★★★★★
5.0
(559 reviews)
130-pt guarantee
$0 to start
then $127/mo
Gmat Prep (x>0)
Source: Beat The GMAT — Data Sufficiency |
Morgoth wrote:x^n = x^(n+2)
x^n = x^n * x^2------ THis is wrong
x^n =0 or x^2 = 1
x= -1 or +1
Statement (1)
if x=-1
x = x^2-2
x= 1-2 = -1.
x=1
x = 1-2 = -1
Sufficient.
Statement (2)
2x < x^5
x=-1
-2 < -1, x negative.
x=1
2 < 1, this case cannot exist. Sufficient.
Thus, D.
OA?
x^n = x^n * x^2
x^n =0 or x^2 = 1
Morgoth..I still have a doubt in your explanation
x^n=x^n*x^2
x^n(1-x^2)=0
x=0,1,-1
Question: Is x positive?
statement 1:
x=x^2-2
x^2-x-2=0
(x-2)(x+1)=0
x=2,-1
Still we cant infer whether is positive or not
Statement 2:
2x<x^5
x^5-2x>0
x(x^4-2)>0
x>0 or x^4>2
even if x=-3 condition x^4>2 is satisfied....
Still we cant infer whether is positive or not
pls let know whats wrong in my explanation....
x^n=x^n*x^2
x^n(1-x^2)=0
x=0,1,-1
Question: Is x positive?
statement 1:
x=x^2-2
x^2-x-2=0
(x-2)(x+1)=0
x=2,-1
Still we cant infer whether is positive or not
Statement 2:
2x<x^5
x^5-2x>0
x(x^4-2)>0
x>0 or x^4>2
even if x=-3 condition x^4>2 is satisfied....
Still we cant infer whether is positive or not
pls let know whats wrong in my explanation....
I guess you guys are misinterpreting the statement.
statement (1)
x = x^2 - 2
x cannot be 0 here because if x=0
0 = 0-2
0 = -2
LHS is not equal to RHS,
You dont have to prove the above statement, the above statement is a given fact.
if x^2=1, we only get one answer i.e. x= -1
Thus, Sufficient.
Hope this helps.
statement (1)
x = x^2 - 2
x cannot be 0 here because if x=0
0 = 0-2
0 = -2
LHS is not equal to RHS,
You dont have to prove the above statement, the above statement is a given fact.
if x^2=1, we only get one answer i.e. x= -1
Thus, Sufficient.
Hope this helps.
