Find all School-related info fast with the new School-Specific MBA Forum

 It is currently 22 May 2015, 10:58

### 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

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

# Events & Promotions

###### Events & Promotions in June
Open Detailed Calendar

# if x+y^2 = (x+y^2)^2 whats is the value of y? 1)x=y^2

Author Message
TAGS:
VP
Joined: 17 Jun 2008
Posts: 1404
Followers: 8

Kudos [?]: 153 [0], given: 0

if x+y^2 = (x+y^2)^2 whats is the value of y? 1)x=y^2 [#permalink]  31 Aug 2008, 18:27
00:00

Difficulty:

(N/A)

Question Stats:

0% (00:00) correct 0% (00:00) wrong based on 0 sessions
if x+y^2 = (x+y^2)^2 whats is the value of y?
1)x=y^2
2)xy^2=0

HELP NEEDED ,i got confused between equations
_________________

cheers
Its Now Or Never

Current Student
Joined: 11 May 2008
Posts: 562
Followers: 7

Kudos [?]: 55 [0], given: 0

Re: DS-equations [#permalink]  31 Aug 2008, 19:18
i think A.

1) x=y^2
so x+y^2 = (x+y^2)^2 becomes 2y^2=4y^4. only 0 satisfies this. so y=0.

2) x +y^2=x^2+ y^4 + 2*x*y^2
or x +y^2=x^2+ y^4
insuff, as we dont know x.
SVP
Joined: 29 Aug 2007
Posts: 2496
Followers: 58

Kudos [?]: 562 [0], given: 19

Re: DS-equations [#permalink]  31 Aug 2008, 20:42
spriya wrote:
if x+y^2 = (x+y^2)^2 whats is the value of y?
1)x=y^2
2)xy^2=0

HELP NEEDED ,i got confused between equations

x+y^2 = (x+y^2)^2
x+y^2 = x^2+2xy^2+y^4

from1: x = y^2
x+y^2 = x^2+2xy^2+y^4
y^2+y^2 = y^4+2y^2y^2+y^4
2y^2 = 4y^4
y^2 = 2y^4
2y^4 - y^2 = 0
y^2 (2y^2 - 1) = 0
y = 0 or +/- 1/4 (but y = 1/4 doesnot satisfy the equation 2y^4 - y^2 = 0)
nsf...

from 2: xy^2 = 0
either x or y or both = 0
x+y^2 = x^2+2xy^2+y^4
x+y^2 = x^2+y^4

if x = 0:
y^2 = y^4
y^4 - y^2 = 0
y2 (y^2 -1) = 0
y = -1, 0, 1
so nsf..

from 1 and 2: y = 0.
C.
_________________

Last edited by GMAT TIGER on 02 Sep 2008, 21:20, edited 1 time in total.
VP
Joined: 17 Jun 2008
Posts: 1404
Followers: 8

Kudos [?]: 153 [0], given: 0

Re: DS-equations [#permalink]  01 Sep 2008, 18:10
GMAT TIGER wrote:
spriya wrote:
if x+y^2 = (x+y^2)^2 whats is the value of y?
1)x=y^2
2)xy^2=0

HELP NEEDED ,i got confused between equations

x+y^2 = (x+y^2)^2
x+y^2 = x^2+2xy^2+y^4

from1: x = y^2
x+y^2 = x^2+2xy^2+y^4
y^2+y^2 = y^4+2y^2y^2+y^4
2y^2 = 4y^4
y^2 = 2y^4
2y^4 - y^2 = 0
y^2 (2y^2 - 1) = 0
y = 0 or 1/2
nsf...

from 2: xy^2 = 0

either x or y or both = 0

x+y^2 = x^2+2xy^2+y^4
x+y^2 = x^2+y^4

if x = 0:
y^2 = y^4
y^4 - y^2 = 0
y2 (y^2 -1) = 0
y = -1, 0, 1

so nsf..

from 1 and 2: y = 0
C.

Oh great explanation !!!common solution of both ,i got wrong that part of the question.
OA is C indeed
_________________

cheers
Its Now Or Never

Current Student
Joined: 11 May 2008
Posts: 562
Followers: 7

Kudos [?]: 55 [0], given: 0

Re: DS-equations [#permalink]  01 Sep 2008, 19:02
GMAT TIGER wrote:
spriya wrote:
if x+y^2 = (x+y^2)^2 whats is the value of y?
1)x=y^2
2)xy^2=0

HELP NEEDED ,i got confused between equations

x+y^2 = (x+y^2)^2
x+y^2 = x^2+2xy^2+y^4

from1: x = y^2
x+y^2 = x^2+2xy^2+y^4
y^2+y^2 = y^4+2y^2y^2+y^4
2y^2 = 4y^4
y^2 = 2y^4........A
2y^4 - y^2 = 0
y^2 (2y^2 - 1) = 0
y = 0 or 1/2.........B
nsf...

from 2: xy^2 = 0

either x or y or both = 0

x+y^2 = x^2+2xy^2+y^4
x+y^2 = x^2+y^4

if x = 0:
y^2 = y^4
y^4 - y^2 = 0
y2 (y^2 -1) = 0
y = -1, 0, 1

so nsf..

from 1 and 2: y = 0
C.

if we substitute B in A, it does not satisfy the eqn, so how 1/2 is a soln?
am i missing something?
Re: DS-equations   [#permalink] 01 Sep 2008, 19:02
Similar topics Replies Last post
Similar
Topics:
If (x+y)^2 = (x+y^2)^2, what is the value of y? 1) x = y^2 1 25 Jul 2010, 12:03
If x + y^2 = (x+y^2)^2, what is the value of y? 1. x=y^2 2. 14 24 May 2006, 07:25
If x + y^2 = (x+y^2)^2, what is the value of y? 1. x=y^2 2. 6 07 Apr 2006, 17:49
If x+y^2=(x+y^2)^2 What si the value of y? 1) x=y^2 2) 1 09 Dec 2005, 07:37
If 0 < x < y, what is the value of (x+y)^2 / (x-y)^2? 2 01 Sep 2005, 05:20
Display posts from previous: Sort by