If xy=1, what is the value of 2(x+y)^2/2(x-y)^2. ( basically 2(x+y)sq/2(x-y)sq.
1. 2
2. 4
3. 8
4. 16
5. 32
Pls let me know..
Thanks!
1. 2
2. 4
3. 8
4. 16
5. 32
Pls let me know..
Thanks!
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
PS
Source: Beat The GMAT — Problem Solving |
Actually no. There was no other infomartion and the answer was in absolute value! This was one of the questions in a practice Gmat Prep test from mba.com.
-
sk818020
- Master | Next Rank: 500 Posts
- Posts: 214
- Location: Houston, TX
- Thanked: 37 times
- GMAT Score:700
If xy=1, what is the value of 2(x+y)^2/2(x-y)^2. ( basically 2(x+y)sq/2(x-y)sq.
1. 2
2. 4
3. 8
4. 16
5. 32
I, like the person who replied first, think there is missing information in this problem. If x and y can be any integer or non-integer, then x and y can be any possible set of non-integers. For example, if x = 4 and y = .25, then:
4 x .25 = 1
If x = .25 and y = 4, then:
.25 x 4 = 1
Other possiblities would include, but are not limited to (also include the vice versa of each example), x = 5 and y = .2, x = 10 and y = .1, x = 20 and y = .05 etc...
All of these examples satisfy the first part of the conditional statement, yet yield varying results for the second part of the conditional statment. In fact, to even begin to answer the question you would have to determine two things; if x and y aree integers and if they are positive or negative because:
1 x 1 =1
and
-1 x -1 = 1
1. 2
2. 4
3. 8
4. 16
5. 32
I, like the person who replied first, think there is missing information in this problem. If x and y can be any integer or non-integer, then x and y can be any possible set of non-integers. For example, if x = 4 and y = .25, then:
4 x .25 = 1
If x = .25 and y = 4, then:
.25 x 4 = 1
Other possiblities would include, but are not limited to (also include the vice versa of each example), x = 5 and y = .2, x = 10 and y = .1, x = 20 and y = .05 etc...
All of these examples satisfy the first part of the conditional statement, yet yield varying results for the second part of the conditional statment. In fact, to even begin to answer the question you would have to determine two things; if x and y aree integers and if they are positive or negative because:
1 x 1 =1
and
-1 x -1 = 1
Are you sure that there was no limes involved at some stage?ajas wrote:Actually no. There was no other infomartion and the answer was in absolute value! This was one of the questions in a practice Gmat Prep test from mba.com.
'cause if you start playing with the expression you will get that the constant that you are looking for can be brought to the following:
c = 1 + (2 / (x - 1/x))^2
where the latter tends to 0 if x approaches +- infinity or 0.
Bests,
J
-
Stuart@KaplanGMAT
- GMAT Instructor
- Posts: 3225
- Location: Toronto
- Thanked: 1710 times
- GMAT Score:800
The question is definitely off.ajas wrote:If xy=1, what is the value of 2(x+y)^2/2(x-y)^2. ( basically 2(x+y)sq/2(x-y)sq.
1. 2
2. 4
3. 8
4. 16
5. 32
Pls let me know..
Thanks!
First, we can cancel out the 2 on top and bottom of the fraction to get:
(x+y)^2/(x-y)^2
simplifying from there:
(x^2 + 2xy + y^2)/(x^2 -2xy + y^2)
= (x^2 + y^2 + 2)/(x^2 + y^2 - 2)
and at this point the solution is "well, it depends on the values of x and y", i.e. there is no numerical solution.
Are you sure the question isn't:
2^(x+y)^2/2^(x-y)^2?
Solving that, we have:
2^(x^2 + 2xy + y^2) / 2^(x^2 -2xy + y^2)
2^((x^2 + 2xy + y^2)-(x^2 -2xy + y^2))
2^(4xy)
(xy=1)
2^4
16... choose (D)!
Stuart Kovinsky | Kaplan GMAT Faculty | Toronto
Kaplan Exclusive: The Official Test Day Experience | Ready to Take a Free Practice Test? | Kaplan/Beat the GMAT Member Discount
BTG100 for $100 off a full course
