xy =1
(2^(x+y)^2)/(2^(x-Y)^2)
now we will use one concept which say that a^b/a^c=a^(b-c)
so we can reduce the given problem to 2 ^(((x+y)^2)-((x-y)^2))
2^(x^2+y^2+2xy -(x^2+y^2 - 2xy)) as we know (a+b)^2=a^2+b^2+2ab and (a-b)^2=a^2+b^2-2ab
2^(4xy) since remaining term will cancel out
2^(4*1)
2^4=16
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
If xy=1
Source: Beat The GMAT — Problem Solving |
Thanks Amising6amising6 wrote:xy =1
(2^(x+y)^2)/(2^(x-Y)^2)
now we will use one concept which say that a^b/a^c=a^(b-c)
so we can reduce the given problem to 2 ^(((x+y)^2)-((x-y)^2))
2^(x^2+y^2+2xy -(x^2+y^2 - 2xy)) as we know (a+b)^2=a^2+b^2+2ab and (a-b)^2=a^2+b^2-2ab
2^(4xy) since remaining term will cancel out
2^(4*1)
2^4=16
Actually, I knew the rule, but I dont' know why I get blocked during the exam with a timer !!.
Silvia
