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.

It appears that you are browsing the GMAT Club forum unregistered!

Signing up is free, quick, and confidential.
Join other 500,000 members and get the full benefits of GMAT Club

Registration gives you:

Tests

Take 11 tests and quizzes from GMAT Club and leading GMAT prep companies such as Manhattan GMAT,
Knewton, and others. All are free for GMAT Club members.

Applicant Stats

View detailed applicant stats such as GPA, GMAT score, work experience, location, application
status, and more

Books/Downloads

Download thousands of study notes,
question collections, GMAT Club’s
Grammar and Math books.
All are free!

Thank you for using the timer!
We noticed you are actually not timing your practice. Click the START button first next time you use the timer.
There are many benefits to timing your practice, including:

Re: For any non-zero a and b that satisfy |ab|=ab and |a|=-a [#permalink]

Show Tags

04 Dec 2012, 01:30

2

This post received KUDOS

Given: |ab| = ab and |a| = -a Question: |b-4| + |ab-b| = ?

**** Looking at |ab| = ab tells us that a and b are either both positive or negative **** Looking at |a| = -a tells us that a must be negative **** Combine two observations: a and b are both negative values

Let a=-1 and b=-1 |b-4| + |ab-b| = |-1-4| + |1-(-1)| = 7

Test a) ab-4 = (-1)(-1)-4 = -3 Test b) 2b-ab-4 = (2)(-1) - (1) - 4 = -7 Test c) ab+4 = 1 + 4 = 5 Test d) ab-2b+4 = 1-2(-1)+4=7 BINGO!

Re: For any non-zero a and b that satisfy |ab| = ab and |a| = -a [#permalink]

Show Tags

04 Jul 2013, 05:11

2

This post received KUDOS

gmatfrenzy750 wrote:

For any non-zero a and b that satisfy |ab| = ab and |a| = -a, |b-4| + |ab-b| =

A. ab-4 B. 2b-ab-4 C. ab+4 D. ab-2b+4 E. 4-ab

1.We need to find whether ab and b are -ve or +ve 2. Since |ab|=ab, ab is +ve 3. Since |a|=-a, a is -ve. 4. From (2) and (3), b is -ve. 5.Since b is -ve b-4 is -ve and so |b-4| becomes -(b-4) 6. Since ab is +ve and b is -ve, ab-b is +ve and |ab-b| becomes ab-b 7. (5) + (6) = -b+4+ab-b= ab-2b+4
_________________

Re: For any non-zero a and b that satisfy |ab| = ab and |a| = -a [#permalink]

Show Tags

09 Jul 2013, 15:49

For any non-zero a and b that satisfy |ab| = ab and |a| = -a, |b-4| + |ab-b| =

|ab| = ab and |a| = -a, |b-4| + |ab-b| =

From |a| = -a we get that a is negative because: |a| = -a and -a must be positive as it is set to an absolute value so: |a| = -(-a) a=a

If a is negative then from |ab| = ab we get that b must be negative as well because: |ab| = (-a)b (-a)b must be positive as it is set to an absolute value |ab| = (-a)(-b) ab=ab

So, both a and b are negative. |b-4| + |ab-b| =

b is negative and ab is positive. Also, because b is negative we know that (ab-b) = (ab-[-b]) = (ab+b)

Re: For any non-zero a and b that satisfy |ab| = ab and |a| = -a [#permalink]

Show Tags

21 Jul 2014, 06:40

Hello from the GMAT Club BumpBot!

Thanks to another GMAT Club member, I have just discovered this valuable topic, yet it had no discussion for over a year. I am now bumping it up - doing my job. I think you may find it valuable (esp those replies with Kudos).

Want to see all other topics I dig out? Follow me (click follow button on profile). You will receive a summary of all topics I bump in your profile area as well as via email.
_________________

Re: For any non-zero a and b that satisfy |ab| = ab and |a| = -a [#permalink]

Show Tags

02 Nov 2015, 10:34

Hello from the GMAT Club BumpBot!

Thanks to another GMAT Club member, I have just discovered this valuable topic, yet it had no discussion for over a year. I am now bumping it up - doing my job. I think you may find it valuable (esp those replies with Kudos).

Want to see all other topics I dig out? Follow me (click follow button on profile). You will receive a summary of all topics I bump in your profile area as well as via email.
_________________

Re: For any non-zero a and b that satisfy |ab| = ab and |a| = -a [#permalink]

Show Tags

01 Jan 2017, 11:22

Hello from the GMAT Club BumpBot!

Thanks to another GMAT Club member, I have just discovered this valuable topic, yet it had no discussion for over a year. I am now bumping it up - doing my job. I think you may find it valuable (esp those replies with Kudos).

Want to see all other topics I dig out? Follow me (click follow button on profile). You will receive a summary of all topics I bump in your profile area as well as via email.
_________________

Campus visits play a crucial role in the MBA application process. It’s one thing to be passionate about one school but another to actually visit the campus, talk...

Its been long time coming. I have always been passionate about poetry. It’s my way of expressing my feelings and emotions. And i feel a person can convey...

Marty Cagan is founding partner of the Silicon Valley Product Group, a consulting firm that helps companies with their product strategy. Prior to that he held product roles at...

Written by Scottish historian Niall Ferguson , the book is subtitled “A Financial History of the World”. There is also a long documentary of the same name that the...