Can somebody help me? : GMAT Quantitative Section
Check GMAT Club App Tracker for the Latest School Decision Releases http://gmatclub.com/AppTrack

It is currently 11 Dec 2016, 04:58
GMAT Club Tests

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.

Close

Request Expert Reply

Events & Promotions

Events & Promotions in June
Open Detailed Calendar

Can somebody help me?

  new topic post reply Question banks Downloads My Bookmarks Reviews Important topics  
Author Message
TAGS:

Hide Tags

Intern
Intern
avatar
Joined: 16 Feb 2012
Posts: 1
Followers: 0

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

Can somebody help me? [#permalink]

Show Tags

New post 16 Feb 2012, 15:46
Can somebody help me with this one

what is (x^2 – 3x)(2x + 5) = 0?

Is it 2x^3+5x^2-6x-15?
Current Student
User avatar
Joined: 12 Sep 2011
Posts: 900
Concentration: Finance, Finance
GMAT 1: 710 Q48 V40
Followers: 137

Kudos [?]: 890 [0], given: 114

Re: Can somebody help me? [#permalink]

Show Tags

New post 16 Feb 2012, 16:28
1
This post was
BOOKMARKED
This would equal 2x^3 + 5x^2 - 6x^2 -15x

Remember to FOIL (first, outer, inner, last) quadratic equations.

This would lead to

(x^2)(2x) + (x^2)(5) + (-3x)(2x) + (-3x)(5) = 2x^3 + 5x^2 - 6x^2 - 15x

First: (x^2)(2x) = 2x^3
Outer: (x^2)(5) = 5x^2
Inner: (-3x)(2x) = -6x^2
Last: (-3x)(5) = -15x
_________________

New to the GMAT Club? <START HERE>

My GMAT and BSchool Tips:


GMAT Club Premium Membership - big benefits and savings

Expert Post
Manhattan GMAT Instructor
User avatar
Joined: 22 Mar 2011
Posts: 924
Followers: 289

Kudos [?]: 782 [0], given: 25

Re: Can somebody help me? [#permalink]

Show Tags

New post 18 Feb 2012, 21:56
Expert's post
1
This post was
BOOKMARKED
You just forgot a power of x. When you multiply (-3x) and (2x), the product is -6x^2. Now we can simplify:

(x^2 – 3x)(2x + 5) = 0

2x^3 + 5x^2 - 6x^2 - 15x = 0

2x^3 - x^2 - 15x = 0

The question now is what you want to do with that equation. If you want to solve, none of the above is necessary. Just factor x out of the first term:

(x^2 – 3x)(2x + 5) = 0
x(x-3)(2x+5)=0

x= 0, +3, or -5/2
_________________


Dmitry Farber | Manhattan GMAT Instructor | New York


Manhattan GMAT Discount | Manhattan GMAT Course Reviews | View Instructor Profile |
Manhattan GMAT Reviews

GMAT Club Legend
GMAT Club Legend
User avatar
Joined: 09 Sep 2013
Posts: 12909
Followers: 563

Kudos [?]: 158 [0], given: 0

Premium Member
Re: Can somebody help me? [#permalink]

Show Tags

New post 26 Oct 2016, 01:50
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.
_________________

GMAT Books | GMAT Club Tests | Best Prices on GMAT Courses | GMAT Mobile App | Math Resources | Verbal Resources

Re: Can somebody help me?   [#permalink] 26 Oct 2016, 01:50
    Similar topics Author Replies Last post
Similar
Topics:
4 Experts publish their posts in the topic Can Someone Please Help Me( Division Strategy) legacydst 9 06 Jul 2011, 16:07
3 Experts publish their posts in the topic At the beginning of last year, Tony's Auto Dealership had rockroars 8 16 Dec 2010, 10:48
help me please... msms 1 24 Oct 2010, 13:14
1 Pleas help me experts xmagedo 11 01 Aug 2010, 02:20
can you help me? hzl 4 09 Oct 2008, 04:14
Display posts from previous: Sort by

Can somebody help me?

  new topic post reply Question banks Downloads My Bookmarks Reviews Important topics  


GMAT Club MBA Forum Home| About| 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®.