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

It is currently 22 Oct 2014, 00:50

Close

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
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.

Events & Promotions

Events & Promotions in June
Open Detailed Calendar

What is the value of |f(x)| - |g(x)| + |f(g(x)| ?

  Question banks Downloads My Bookmarks Reviews Important topics  
Author Message
TAGS:
Expert Post
Math Expert
User avatar
Joined: 02 Sep 2009
Posts: 23363
Followers: 3605

Kudos [?]: 28747 [0], given: 2846

Re: function [#permalink] New post 22 May 2013, 01:40
Expert's post
fozzzy wrote:
Vips0000 wrote:
vinnik wrote:
Let f(a) = a - 5
g(b) = 5 - b.

What is the value of |f(x)| - |g(x)| + |f(g(x)| ?

A). |x - 10|
B). 3x + 10
C). |x|
D). |x - 5|
E). x

What is wrong with
[Reveal] Spoiler:
E


Thanks & Regards
Vinni



From question:

|f(x)| = |x-5|
|g(x)| =|5-x|
|f(g(x)| = |f(5-x)| = |5-x-5| =|-x|

Now:
|f(x)| - |g(x)| + |f(g(x)|

= |x-5| -|5-x|+|-x|

=|x-5|- |x-5|+|x|

=|x|

Ans C.

It can not be E because x <> |x| for any negative value of x.

Hope it helps..:)


How did you get that part I didn't understand that I understood the rest why is it 5-x-5?


This post might help: what-is-the-value-of-f-x-g-x-f-g-x-141632.html#p1180176
_________________

NEW TO MATH FORUM? PLEASE READ THIS: ALL YOU NEED FOR QUANT!!!

PLEASE READ AND FOLLOW: 11 Rules for Posting!!!

RESOURCES: [GMAT MATH BOOK]; 1. Triangles; 2. Polygons; 3. Coordinate Geometry; 4. Factorials; 5. Circles; 6. Number Theory; 7. Remainders; 8. Overlapping Sets; 9. PDF of Math Book; 10. Remainders; 11. GMAT Prep Software Analysis NEW!!!; 12. SEVEN SAMURAI OF 2012 (BEST DISCUSSIONS) NEW!!!; 12. Tricky questions from previous years. NEW!!!;

COLLECTION OF QUESTIONS:
PS: 1. Tough and Tricky questions; 2. Hard questions; 3. Hard questions part 2; 4. Standard deviation; 5. Tough Problem Solving Questions With Solutions; 6. Probability and Combinations Questions With Solutions; 7 Tough and tricky exponents and roots questions; 8 12 Easy Pieces (or not?); 9 Bakers' Dozen; 10 Algebra set. ,11 Mixed Questions, 12 Fresh Meat

DS: 1. DS tough questions; 2. DS tough questions part 2; 3. DS tough questions part 3; 4. DS Standard deviation; 5. Inequalities; 6. 700+ GMAT Data Sufficiency Questions With Explanations; 7 Tough and tricky exponents and roots questions; 8 The Discreet Charm of the DS ; 9 Devil's Dozen!!!; 10 Number Properties set., 11 New DS set.


What are GMAT Club Tests?
25 extra-hard Quant Tests

Get the best GMAT Prep Resources with GMAT Club Premium Membership

Kaplan Promo CodeKnewton GMAT Discount CodesGMAT Pill GMAT Discount Codes
Director
Director
avatar
Joined: 29 Nov 2012
Posts: 929
Followers: 12

Kudos [?]: 311 [0], given: 543

Re: What is the value of |f(x)| - |g(x)| + |f(g(x)| ? [#permalink] New post 22 May 2013, 05:56
one more question if we were given X is positive or negative then the answer would be E?
_________________

Click +1 Kudos if my post helped...

Amazing Free video explanation for all Quant questions from OG 13 and much more http://www.gmatquantum.com/og13th/

GMAT Prep software What if scenarios gmat-prep-software-analysis-and-what-if-scenarios-146146.html

VP
VP
User avatar
Status: Far, far away!
Joined: 02 Sep 2012
Posts: 1125
Location: Italy
Concentration: Finance, Entrepreneurship
GPA: 3.8
Followers: 113

Kudos [?]: 1191 [0], given: 219

GMAT ToolKit User
Re: What is the value of |f(x)| - |g(x)| + |f(g(x)| ? [#permalink] New post 22 May 2013, 06:08
fozzzy wrote:
one more question if we were given X is positive or negative then the answer would be E?


Not sure of what you mean, but the answer is C for every value of x (+ve, -ve or =0)
_________________

It is beyond a doubt that all our knowledge that begins with experience.

Kant , Critique of Pure Reason

Tips and tricks: Inequalities , Mixture | Review: MGMAT workshop
Strategy: SmartGMAT v1.0 | Questions: Verbal challenge SC I-II- CR New SC set out !! , My Quant

Rules for Posting in the Verbal Forum - Rules for Posting in the Quant Forum[/size][/color][/b]

Director
Director
avatar
Joined: 29 Nov 2012
Posts: 929
Followers: 12

Kudos [?]: 311 [0], given: 543

Re: What is the value of |f(x)| - |g(x)| + |f(g(x)| ? [#permalink] New post 22 May 2013, 07:41
As per Vips000 solution after you solve we get =|x|

now if we were given an additional constraint that X is positive then we can solve for the modulus right?
_________________

Click +1 Kudos if my post helped...

Amazing Free video explanation for all Quant questions from OG 13 and much more http://www.gmatquantum.com/og13th/

GMAT Prep software What if scenarios gmat-prep-software-analysis-and-what-if-scenarios-146146.html

VP
VP
User avatar
Status: Far, far away!
Joined: 02 Sep 2012
Posts: 1125
Location: Italy
Concentration: Finance, Entrepreneurship
GPA: 3.8
Followers: 113

Kudos [?]: 1191 [0], given: 219

GMAT ToolKit User
Re: What is the value of |f(x)| - |g(x)| + |f(g(x)| ? [#permalink] New post 22 May 2013, 07:45
fozzzy wrote:
As per Vips000 solution after you solve we get =|x|

now if we were given an additional constraint that X is positive then we can solve for the modulus right?


If we know that x is positive then we can solve the modulus and obtain |x|=x, yes you're right.

But be careful, in this case both c and e would be correct

C). |x| => x

E). x
They are the same.

Hope it's clear
_________________

It is beyond a doubt that all our knowledge that begins with experience.

Kant , Critique of Pure Reason

Tips and tricks: Inequalities , Mixture | Review: MGMAT workshop
Strategy: SmartGMAT v1.0 | Questions: Verbal challenge SC I-II- CR New SC set out !! , My Quant

Rules for Posting in the Verbal Forum - Rules for Posting in the Quant Forum[/size][/color][/b]

SVP
SVP
User avatar
Joined: 06 Sep 2013
Posts: 1737
Location: United States
Concentration: Finance
GMAT 1: 710 Q48 V39
WE: Corporate Finance (Investment Banking)
Followers: 14

Kudos [?]: 191 [0], given: 295

GMAT ToolKit User
Re: What is the value of |f(x)| - |g(x)| + |f(g(x)| ? [#permalink] New post 20 Nov 2013, 07:51
vinnik wrote:
Let f(a) = a - 5
g(b) = 5 - b.

What is the value of |f(x)| - |g(x)| + |f(g(x)| ?

A. |x - 10|
B. 3x + 10
C. |x|
D. |x - 5|
E. x

What is wrong with
[Reveal] Spoiler:
E


Thanks & Regards
Vinni


Great problem!

Ya, just to keep it short and sweet

|x - 5| - |5-x| + |-x|

The first two terms are the same by property and the minus sign on the last term doesn't matter cause it will be positive under an absolute value.

So we are left with |x|

Kudos Rain!!
Cheers
J :)
Re: What is the value of |f(x)| - |g(x)| + |f(g(x)| ?   [#permalink] 20 Nov 2013, 07:51
    Similar topics Author Replies Last post
Similar
Topics:
13 Experts publish their posts in the topic If f(x) = 5x^2 - 4 and g(x) = 3x + 1, then what is the sum Bunuel 10 09 Jul 2014, 05:06
7 Experts publish their posts in the topic what is the greatest possible value of the function f(x)? venkateshreddy 5 07 Apr 2014, 02:47
1 Experts publish their posts in the topic If f(x) = x^3 + 1, and g(x) = 2x, for what value of x does josemnz83 3 10 Jul 2013, 11:52
Experts publish their posts in the topic If f(x) = x^2 - x - 6, is f(x) ≥ g(x)? WoundedTiger 9 04 Jan 2013, 01:21
5 What is the minimal value of function f(x)? manalq8 5 25 Nov 2011, 14:24
Display posts from previous: Sort by

What is the value of |f(x)| - |g(x)| + |f(g(x)| ?

  Question banks Downloads My Bookmarks Reviews Important topics  

Go to page   Previous    1   2   [ 26 posts ] 



GMAT Club MBA Forum Home| About| Privacy Policy| Terms and Conditions| GMAT Club Rules| Contact| Sitemap

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®.