It is currently 19 Sep 2017, 14:05

### 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-5)^2 } = 5 - x ? 1. -x|x| > 0 2. 5 -x

Author Message
Manager
Joined: 05 Feb 2007
Posts: 139

Kudos [?]: 8 [0], given: 7

Is \sqrt{(x-5)^2 } = 5 - x ? 1. -x|x| > 0 2. 5 -x [#permalink]

### Show Tags

28 Jan 2009, 09:16
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.

Is

$$\sqrt{(x-5)^2 } = 5 - x$$ ?

1. -x|x| > 0
2. 5 -x > 0

Kudos [?]: 8 [0], given: 7

Senior Manager
Joined: 30 Nov 2008
Posts: 485

Kudos [?]: 347 [0], given: 15

Schools: Fuqua
Re: DS - Number Properties, sq root [#permalink]

### Show Tags

28 Jan 2009, 09:34
IMO D.

From Question stem, is sqrt((x-5) ^2) = (5 - x) ==> gets boiled down to trying to answer IS x-5 X 5 - x.(Reason being in GMAT, it is always true that sqrt(x^2) is always x.) which inturn boils down to answering the question = IS X = 5?

From Stmt 1, -x|x| > 0 ==> this is possible only when x < 0. For any value of X that is less than 0, x-5 <> 5 - x. This is sufficient to ans the question stem as NO. Hence it is sufficient.

From stmt 2, 5 - x > 0 ==> X < 5. For any value of X that is less than 5, x-5 <> 5 - x. This is sufficient to ans the question stem as NO. Hence it is sufficient.

Kudos [?]: 347 [0], given: 15

Senior Manager
Joined: 02 Nov 2008
Posts: 276

Kudos [?]: 112 [0], given: 2

Re: DS - Number Properties, sq root [#permalink]

### Show Tags

28 Jan 2009, 23:41
mrsmarthi wrote:
IMO D.

From Question stem, is sqrt((x-5) ^2) = (5 - x) ==> gets boiled down to trying to answer IS x-5 X 5 - x.(Reason being in GMAT, it is always true that sqrt(x^2) is always x.) which inturn boils down to answering the question = IS X = 5?

From Stmt 1, -x|x| > 0 ==> this is possible only when x < 0. For any value of X that is less than 0, x-5 <> 5 - x. This is sufficient to ans the question stem as NO. Hence it is sufficient.

From stmt 2, 5 - x > 0 ==> X < 5. For any value of X that is less than 5, x-5 <> 5 - x. This is sufficient to ans the question stem as NO. Hence it is sufficient.

Great explanation. I also came up with D.

Kudos [?]: 112 [0], given: 2

SVP
Joined: 17 Jun 2008
Posts: 1540

Kudos [?]: 278 [0], given: 0

Re: DS - Number Properties, sq root [#permalink]

### Show Tags

29 Jan 2009, 03:25
sqrt([x-5]^2) = |x-5|

Now, if x-5 > 0 then |x-5| = x-5
But, if x-5 < 0 then |x-5| = 5-x.

Thus, in order for the euality in the question to be true, x-5 has to be less than 0 or x < 5.

From stmt1: The inequality is possible only when x < 0. That means, x is already less than 5. Hence, sufficient to answer the question.

From stmt2: x-5 < 0. Again, sufficient to answer the question.

Hence, D.

Kudos [?]: 278 [0], given: 0

Re: DS - Number Properties, sq root   [#permalink] 29 Jan 2009, 03:25
Display posts from previous: Sort by