Is x > 0? (1) |x + 3| = 4x 3 (2) |x 3| = |2x 3

Oldest

Best Reply

Author

Message

TAGS:

Senior Manager

Joined: 24 Feb 2008

Posts: 351

Schools: UCSD ($) , UCLA, USC ($), Stanford

Followers: 67

Kudos [?]: 699 [0], given: 2

Is x > 0? (1) |x + 3| = 4x 3 (2) |x 3| = |2x 3 [#permalink]

30 Mar 2008, 12:46

00:00

Question Stats:

0% (00:00) correct

0% (00:00) wrong

based on 0 sessions

Is x > 0?

(1) |x + 3| = 4x – 3

(2) |x – 3| = |2x – 3|
_________________

Chinese Democracy is misunderstood...at your nearest BestBuy.

Best AWA guide here: how-to-get-6-0-awa-my-guide-64327.html

CEO

Joined: 17 Nov 2007

Posts: 3596

Concentration: Entrepreneurship, Other

Schools: Chicago (Booth) - Class of 2011

GMAT 1: 750 Q50 V40

Followers: 232

Kudos [?]: 1301 [0], given: 346

Re: DS: absolute value [#permalink]

30 Mar 2008, 12:58

A

1. |x + 3| = 4x – 3 --> 4x-3>0 --> x>3/4 --> sufficient

2. |x – 3| = |2x – 3|. x=0 and x=2 satisfy the condition. insufficient
_________________

iOS/Android: GMAT ToolKit - The bestselling GMAT prep app | GMAT Club (free) | PrepGame | GRE ToolKit | LSAT ToolKit
PROMO: Are you an exiting GMAT ToolKit (iOS) user? Get GMAT ToolKit 2 (iOS) for only $0.99 (read more)
Math: GMAT Math Book ||| General: GMATTimer ||| Chicago Booth: Slide Presentation
The People Who Are Crazy Enough to Think They Can Change the World, Are the Ones Who Do.

Manager

Joined: 08 Oct 2004

Posts: 224

Followers: 0

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

Re: DS: absolute value [#permalink]

30 Mar 2008, 14:16

E?
How about Ix+3I> 0
Solves to be X=2

Both S1 and S2 give X=0/2
E
_________________

Believe in yourself.

SVP

Joined: 04 May 2006

Posts: 1946

Schools: CBS, Kellogg

Followers: 10

Kudos [?]: 168 [0], given: 1

Re: DS: absolute value [#permalink]

30 Mar 2008, 20:31

walker wrote:

A

1. |x + 3| = 4x – 3 --> 4x-3>0 --> x>3/4 --> sufficient

2. |x – 3| = |2x – 3|. x=0 and x=2 satisfy the condition. insufficient

Walker, you always walk ahead! :lol:

1. specific x = 3 so sufficient
2. the same above

A
_________________

Find out what's new at GMAT Club - latest features and updates

Current Student

Joined: 28 Dec 2004

Posts: 3439

Location: New York City

Schools: Wharton'11 HBS'12

Followers: 11

Kudos [?]: 134 [0], given: 2

Re: DS: absolute value [#permalink]

30 Mar 2008, 20:57

I got statement 2 to be insuff by just eye balling the equation and realizing that 2 and 0 were solutions..however I am having a hard time putting statemnt 2 in a equation and finding the critical points...can someone pls expand and show how to get the solutions to the following equation
|x-3|=|2x-3|...

CEO

Joined: 17 Nov 2007

Posts: 3596

Concentration: Entrepreneurship, Other

Schools: Chicago (Booth) - Class of 2011

GMAT 1: 750 Q50 V40

Followers: 232

Kudos [?]: 1301 [0], given: 346

Re: DS: absolute value [#permalink]

30 Mar 2008, 22:07

fresinha12 wrote:

1. we have to find key points, in which modules are zero:
1.1. x-3=0 --> x=3
1.2. 2x-3=0 --> x=1.5

2. Now, we carefully eliminate modulas:
2.1. for x e (-∞,1.5)&(3,+∞): x-3=2x-3 --> x=0 (x is in the range)
2.2. for x e [1.5,3]: x-3=-2x+3 --> 3x=6 --> x=2 (x is in the range)

So, we have two solutions: 0 and 2
_________________

CEO

Joined: 29 Aug 2007

Posts: 2530

Followers: 41

Kudos [?]: 358 [0], given: 19

Re: DS: absolute value [#permalink]

31 Mar 2008, 00:52

chineseburned wrote:

Is x > 0?

(1) |x + 3| = 4x – 3
(2) |x – 3| = |2x – 3|

1: |x + 3| = 4x – 3

if |x + 3| is +ve, x + 3 = 4x – 3 and x = 2.
if |x + 3| is -ve, -x -3 = 4x – 3 and x = 0.

x = 2 works for the equality but x = 0 doesnot make the equation equal. so x cannot be 0. then x must be 2. so suff.

2:|x – 3| = |2x – 3|

if |x – 3| and |2x – 3| are either -ves (or +ves), x – 3 = 2x – 3. x = 0
if |x – 3| is +ve (or -ve) and |2x – 3| is -ve (or +ve), x - 3 = -2x + 3. x = 2

x = 0 and 2 both satisfiy the equation. so not suff....

A is it...
_________________

Verbal: new-to-the-verbal-forum-please-read-this-first-77546.html
Math: new-to-the-math-forum-please-read-this-first-77764.html
Gmat: everything-you-need-to-prepare-for-the-gmat-revised-77983.html

GT

Manager

Joined: 08 Oct 2004

Posts: 224

Followers: 0

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

Re: DS: absolute value [#permalink]

31 Mar 2008, 05:36

Yes, A it is. I see where I messed up.
I solved the inequality but did not check whether both the conditions are satisfied with the value "x=0".
_________________

Believe in yourself.

Re: DS: absolute value [#permalink] 31 Mar 2008, 05:36

	Similar topics	Author	Replies	Last post
Similar Topics:	Is x > 0? (1) \|x + 3\| = 4x 3 (2) \|x 3\| = \|2x 3	iamba	8	01 Jul 2007, 09:52
	Is x > 0, 1. \|x + 3\| = 4x - 3 2. \|x - 3\| = \|2x -3\|	asaf	6	18 Aug 2007, 16:13
	Is x > 0? (1) \|x + 3\| = 4x 3 (2) \|x 3\| = \|2x 3	jimjohn	8	31 Oct 2007, 07:49
	Is x > 0? (1) \|x + 3\| = 4x 3 (2) \|x 3\| = \|2x 3	alimad	11	24 Nov 2007, 06:37
	Is x > 0? (1) \|x + 3\| = 4x 3 (2) \|x 3\| = \|2x 3	Anon	1	22 Jul 2008, 00:38

Is x > 0? (1) |x + 3| = 4x 3 (2) |x 3| = |2x 3

Main navigation

GMAT Resources

Partners

MBA Resources

GMAT ® is a registered trademark of the Graduate Management Admission Council ® (GMAC ®). GMAT Club's website has not been reviewed or endorsed by GMAC.

GMAT Courses

Admissions Consulting

Is x > 0? (1) |x + 3| = 4x 3 (2) |x 3| = |2x 3

Is x > 0? (1) |x + 3| = 4x 3 (2) |x 3| = |2x 3

Main navigation

GMAT Resources

Partners

MBA Resources