It is currently 27 Jun 2017, 21:24

### 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

# Is sqrt[(x-3)^2] = (3-x)^2 ? (1) x ≠ 3 (2) – x | x | > 0

Author Message
VP
Joined: 03 Apr 2007
Posts: 1342
Is sqrt[(x-3)^2] = (3-x)^2 ? (1) x ≠ 3 (2) – x | x | > 0 [#permalink]

### Show Tags

16 May 2008, 17:43
00:00

Difficulty:

(N/A)

Question Stats:

0% (00:00) correct 0% (00:00) wrong based on 0 sessions

### HideShow timer Statistics

This topic is locked. If you want to discuss this question please re-post it in the respective forum.

20. Is sqrt[(x-3)^2] = (3-x)^2 ?
(1) x ≠ 3
(2) – x | x | > 0

Director
Joined: 14 Jan 2007
Posts: 774

### Show Tags

16 May 2008, 18:05
should be 'B'.

Stmt1:
for x = 2, sqrt[(x-3)^2] = (3-x)^2
for x=5, sqrt[(x-3)^2] does not equal to (3-x)^2
insuff
Stmt2: deduces x< 0
for x<0, sqrt[(x-3)^2] does not equal to (3-x)^2, so suff
VP
Joined: 03 Apr 2007
Posts: 1342

### Show Tags

17 May 2008, 09:26
vshaunak@gmail.com wrote:
should be 'B'.

Stmt1:
for x = 2, sqrt[(x-3)^2] = (3-x)^2
for x=5, sqrt[(x-3)^2] does not equal to (3-x)^2
insuff
Stmt2: deduces x< 0
for x<0, sqrt[(x-3)^2] does not equal to (3-x)^2, so suff

Can you please explain how the 2nd stmnt deduces to x<0?
Intern
Joined: 29 Apr 2008
Posts: 21

### Show Tags

17 May 2008, 09:48
goalsnr wrote:

Can you please explain how the 2nd stmnt deduces to x<0?

2nd statement -x |x| > 0
|x| >0 for all x
thus -x > 0 => x <0

hope this helps
VP
Joined: 03 Apr 2007
Posts: 1342

### Show Tags

18 May 2008, 06:39
goalsnr wrote:
20. Is sqrt[(x-3)^2] = (3-x)^2 ?
(1) x ≠ 3
(2) – x | x | > 0

Can't we solve this problem by solving for x ? Iam confused what the question really asks for.

sqrt[(x-3)^2] = (3-x)^2

By solvingthe above equation
(x-3) = (3-x)^2

-> x^2 -7x +12 = 0

solving further
(x-3)(x-4)=0

x=3 0r x=4

Stat 1: since x ≠ 3 we can conclude x =4 Suff
stat2 : x<0, suff

Is my approach correct?
Senior Manager
Joined: 20 Feb 2008
Posts: 295
Location: Bangalore, India
Schools: R1:Cornell, Yale, NYU. R2: Haas, MIT, Ross

### Show Tags

18 May 2008, 07:04
Hi I agree with stat B

Stat1. Both x=2 and x=4 give a YES for the question but 5 gives a NO.So insifficient

Stat2. For all values of x<0 ; sqrt[(x-3)^2] is not equal to (3-x)^2 . So sufficient.

I think the trick is to plug in numbers
VP
Joined: 03 Apr 2007
Posts: 1342

### Show Tags

18 May 2008, 07:17
ventivish wrote:
Hi I agree with stat B

Stat1. Both x=2 and x=4 give a YES for the question but 5 gives a NO.So insifficient

Stat2. For all values of x<0 ; sqrt[(x-3)^2] is not equal to (3-x)^2 . So sufficient.

I think the trick is to plug in numbers

My question is why the solving for x will not work?
Senior Manager
Joined: 20 Feb 2008
Posts: 295
Location: Bangalore, India
Schools: R1:Cornell, Yale, NYU. R2: Haas, MIT, Ross

### Show Tags

18 May 2008, 07:49
goalsnr wrote:
ventivish wrote:
Hi I agree with stat B

Stat1. Both x=2 and x=4 give a YES for the question but 5 gives a NO.So insifficient

Stat2. For all values of x<0 ; sqrt[(x-3)^2] is not equal to (3-x)^2 . So sufficient.

I think the trick is to plug in numbers

My question is why the solving for x will not work?

You need to be careful with solving for variables.
If you solve for sqrt[(x-3)^2]=(3-x)^2
your calculations assume that (x-3) is positive, it could be that x-3 is negative in which case your equation would look like this:
-(x-3)=(3-x)^2
This would solve for x=2 and x=3

So you still have 2 options, x=2 and x=4 which is insufficient.
If you tried plugging in numbers you would just save time.
Hope this helps!
VP
Joined: 03 Apr 2007
Posts: 1342

### Show Tags

18 May 2008, 17:36
Finally I get it

num to plug in sqrt[(x-3)^2] (3-x)^2

0 3 9
1 2 4
2 1 1
-1 4 16
-2 5 25

values 0,1,2 show why stat1 is insuff

values -1, -2 show why stat2 is suff

OA is B
Re: DS- squareroot   [#permalink] 18 May 2008, 17:36
Display posts from previous: Sort by

# Is sqrt[(x-3)^2] = (3-x)^2 ? (1) x ≠ 3 (2) – x | x | > 0

 Powered by phpBB © phpBB Group and phpBB SEO Kindly note that the GMAT® test is a registered trademark of the Graduate Management Admission Council®, and this site has neither been reviewed nor endorsed by GMAC®.