Target Test Prep's 2024 GMAT Focus Edition prep is discounted for the BTG community!

Redeem
Target Test Prep
5-Day Free Trial
5-day free, full-access trial TTP

Available with Beat the GMAT members only code

MORE DETAILS
Target Test Prep
Magoosh
Magoosh
Study with Magoosh GMAT prep

Available with Beat the GMAT members only code

MORE DETAILS
Magoosh

Just don't see how to get started with this one

This topic has expert replies
Post new topic Post Reply
Previous Topic Next Topic
User avatar
Newbie | Next Rank: 10 Posts
Posts: 2
Joined: Fri May 11, 2012 11:57 am

Just don't see how to get started with this one

by GMATBeater77 » Fri May 11, 2012 12:03 pm
I don't see how to solve a problem like this one:

If x is different from 3, then (3x(x-3) -x +3)/(x-3) = ...

A : X+1
B : X-3
C : 3x +1
D : 3x -1
E : 3X +3

Any help welcome! Thanks!
Top
Junior | Next Rank: 30 Posts
Posts: 29
Joined: Fri Sep 25, 2009 9:26 am

by Pugalenthi » Fri May 11, 2012 12:15 pm
The answer is D
3x(x-3) -x +3/x-3 could be written as
3x(x-3) -1(x-3)/x-3
(3x-1)(x-3)/x-3
3x -1
Top
User avatar
Newbie | Next Rank: 10 Posts
Posts: 2
Joined: Fri May 11, 2012 11:57 am

by GMATBeater77 » Fri May 11, 2012 12:45 pm
Thanks, that's totally correct.
I understand your approach however I wouldn't have come to this solution myself.
Is there some kind of strategy to approach these kind of problems.
Top
User avatar
GMAT Instructor
Posts: 1248
Joined: Thu Mar 29, 2012 2:57 pm
Location: Everywhere
Thanked: 503 times
Followed by:192 members
GMAT Score:780

by Bill@VeritasPrep » Fri May 11, 2012 4:03 pm
GMATBeater77 wrote:Thanks, that's totally correct.
I understand your approach however I wouldn't have come to this solution myself.
Is there some kind of strategy to approach these kind of problems.
The biggest thing is to look for an opportunity to factor out a common term. In this case, the fact that we have (x-3) in the numerator and the denominator should point us in the right direction.
Join Veritas Prep's 2010 Instructor of the Year, Matt Douglas for GMATT Mondays

Visit the Veritas Prep Blog

Try the FREE Veritas Prep Practice Test
Top
User avatar
GMAT Instructor
Posts: 15539
Joined: Tue May 25, 2010 12:04 pm
Location: New York, NY
Thanked: 13060 times
Followed by:1906 members
GMAT Score:790

by GMATGuruNY » Fri May 11, 2012 7:00 pm
GMATBeater77 wrote:I don't see how to solve a problem like this one:

If x is different from 3, then (3x(x-3) -x +3)/(x-3) = ...

A : X+1
B : X-3
C : 3x +1
D : 3x -1
E : 3X +3

Any help welcome! Thanks!
Let x=0.
Then (3x(x-3) -x +3)/(x-3) = (0-0+3)/(0-3) = -1. This is our target.

Now we plug x=0 into the answers to see which yields our target of -1.
Only D works:
3x-1 = 3(0)-1 = -1.

The correct answer is D.
Private tutor exclusively for the GMAT and GRE, with over 20 years of experience.
Followed here and elsewhere by over 1900 test-takers.
I have worked with students based in the US, Australia, Taiwan, China, Tajikistan, Kuwait, Saudi Arabia -- a long list of countries.
My students have been admitted to HBS, CBS, Tuck, Yale, Stern, Fuqua -- a long list of top programs.

As a tutor, I don't simply teach you how I would approach problems.
I unlock the best way for YOU to solve problems.

For more information, please email me (Mitch Hunt) at [email protected].
Student Review #1
Student Review #2
Student Review #3
Top
Post new topic Post Reply
• Page 1 of 1