NEW HERE? LEARN MORE
closeclose
Last visit was: 25 Apr 2024, 09:01 It is currently 25 Apr 2024, 09:01
Decision Tracker
My Rewards
New posts
New comers' posts

Close
GMAT Club Daily Prep
Thank you for using the timer - this advanced tool can estimate your performance and suggest more practice questions. We have subscribed you to Daily Prep Questions via email.

Customized
for You

we will pick new questions that match your level based on your Timer History

Track
Your Progress

every week, we’ll send you an estimated GMAT score based on your performance

Practice
Pays

we will pick new questions that match your level based on your Timer History
Not interested in getting valuable practice questions and articles delivered to your email? No problem, unsubscribe here.
Go to My Error Log Learn more
Close
Request Expert Reply
Confirm Cancel

If X^2 + Y^2 = A +3, XY = 7 and (X + Y)^2 = 25, what is the value of A

SORT BY:
Date
Kudos
Tags:
Find Similar Topics 
Show Tags
Hide Tags
User avatar
L
Bunuel
Math Expert
Joined: 02 Sep 2009
Posts: 92914
Own Kudos [?]: 618958 [0]
Given Kudos: 81595
Send PM
CAT Tests Forum Quiz Mode
If X^2 + Y^2 = A +3, XY = 7 and (X + Y)^2 = 25, what is the value of A [#permalink] New post   12 Sep 2019, 01:13
Expert Reply
00:00
A
B
C
D
E

Difficulty:

5% (low)

Question Stats:

89% (00:58) correct 11% (01:32) wrong based on 94 sessions
Hide Show timer Statistics
If \(X^2 + Y^2 = A +3\), \(XY = 7\) and \((X + Y)^2 = 25\), what is the value of A?

A. 11.
B. 8.
C. 6.
D. 5.
E. 4.
ShowHide Answer
Official Answer
B
User avatar
L
firas92
Current Student
Joined: 16 Jan 2019
Posts: 631
Own Kudos [?]: 1444 [1]
Given Kudos: 144
Location: India
Concentration: General Management
Schools: Tepper '23 (M$) Foster '23 (D)
GMAT 1: 740 Q50 V40
WE:Sales (Other)
Send PM
Reviews Badge
Re: If X^2 + Y^2 = A +3, XY = 7 and (X + Y)^2 = 25, what is the value of A [#permalink] New post   12 Sep 2019, 01:17
1
Kudos
\((X+Y)^2 = X^2+Y^2+2XY\)

\(25=A+3+2(7)\)

\(A=25-14-3\)

\(A=8\)

Answer is (B)
User avatar
L
ScottTargetTestPrep
Target Test Prep Representative
Joined: 14 Oct 2015
Status:Founder & CEO
Affiliations: Target Test Prep
Posts: 18761
Own Kudos [?]: 22051 [1]
Given Kudos: 283
Location: United States (CA)
Send PM
Re: If X^2 + Y^2 = A +3, XY = 7 and (X + Y)^2 = 25, what is the value of A [#permalink] New post   16 Sep 2019, 11:36
1
Kudos
Expert Reply
Bunuel wrote:
If \(X^2 + Y^2 = A +3\), \(XY = 7\) and \((X + Y)^2 = 25\), what is the value of A?

A. 11.
B. 8.
C. 6.
D. 5.
E. 4.


If we expand (X + Y)^2, we have:

X^2 + Y^2 + 2XY = 25

Since X^2 + Y^2 = A + 3, and since XY = 7, we can substitute, obtaining:

A + 3 + 14 = 25

A = 8

Answer: B
User avatar
L
Kinshook
GMAT Club Legend
GMAT Club Legend
Joined: 03 Jun 2019
Posts: 5344
Own Kudos [?]: 3964 [0]
Given Kudos: 160
Location: India
Schools: HBS '22 CBS '22 Wharton '22
GMAT 1: 690 Q50 V34
WE:Engineering (Transportation)
Send PM
Reviews Badge
Re: If X^2 + Y^2 = A +3, XY = 7 and (X + Y)^2 = 25, what is the value of A [#permalink] New post   04 Aug 2020, 23:37
Bunuel wrote:
If \(X^2 + Y^2 = A +3\), \(XY = 7\) and \((X + Y)^2 = 25\), what is the value of A?

A. 11.
B. 8.
C. 6.
D. 5.
E. 4.


Asked: If \(X^2 + Y^2 = A +3\), \(XY = 7\) and \((X + Y)^2 = 25\), what is the value of A?

Since (X+Y)^2 = X^2 + Y^2 + 2XY

25 = A + 3 + 14
A = 8

IMO B
User avatar
P
Nipungupta9081
School Moderator - INSEAD Masters
Joined: 07 Jan 2020
Posts: 510
Own Kudos [?]: 265 [0]
Given Kudos: 193
Location: India
GPA: 4
WE:Analyst (Accounting)
Send PM
Re: If X^2 + Y^2 = A +3, XY = 7 and (X + Y)^2 = 25, what is the value of A [#permalink] New post   15 Aug 2020, 04:09
IMO B

X^2 + Y^2 = 25
x^2 + Y^2 + 2XY = 25

Putting the values

A + 3 + 2*7 = 25
A + 3 = 25 - 14
A = 11 - 3 = 8
GMAT Club Bot
gmatclubot
Re: If X^2 + Y^2 = A +3, XY = 7 and (X + Y)^2 = 25, what is the value of A [#permalink]
15 Aug 2020, 04:09
Moderators:
Bunuel
Math Expert
92914 posts
yashikaaggarwal
Senior Moderator - Masters Forum
3137 posts

Powered by phpBB © phpBB Group | Emoji artwork provided by EmojiOne
Main navigation
GMAT Resources
Partners
MBA Resources
www.gmac.com|www.mba.com | | GMAT Club Rules | Terms and Conditions