GMAT Question of the Day - Daily to your Mailbox; hard ones only

It is currently 13 Dec 2019, 16:06

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

Confirm Cancel

3x^2 + 2x - 8 =

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

Hide Tags

Find Similar Topics 
Intern
Intern
avatar
Joined: 05 May 2012
Posts: 12
3x^2 + 2x - 8 =  [#permalink]

Show Tags

New post 13 May 2012, 22:53
1
2
00:00
A
B
C
D
E

Difficulty:

  25% (medium)

Question Stats:

72% (01:14) correct 28% (01:30) wrong based on 185 sessions

HideShow timer Statistics

3x^2 + 2x - 8 =

A. (3x-4)(x-2)
B. (3x-4)(x+2)
C. (3x-4)(x-2)
D. (3x-2)(x+4)
E. none of above
SVP
SVP
User avatar
P
Status: Top MBA Admissions Consultant
Joined: 24 Jul 2011
Posts: 1919
GMAT 1: 780 Q51 V48
GRE 1: Q800 V740
Re: 3x^2 + 2x - 8 =  [#permalink]

Show Tags

New post 13 May 2012, 23:15
1
3x^2 + 2x - 8
= 3x^2 + 6x - 4x - 8
= 3x (x + 2) - 4 (x+2)
= (3x-4) (x+2)

Option B
_________________
GyanOne [www.gyanone.com]| Premium MBA and MiM Admissions Consulting

Awesome Work | Honest Advise | Outstanding Results

Reach Out, Lets chat!
Email: info at gyanone dot com | +91 98998 31738 | Skype: gyanone.services
Math Expert
User avatar
V
Joined: 02 Sep 2009
Posts: 59721
Re: 3x^2 + 2x - 8 =  [#permalink]

Show Tags

New post 14 May 2012, 00:09
Senior Manager
Senior Manager
User avatar
Joined: 23 Oct 2010
Posts: 318
Location: Azerbaijan
Concentration: Finance
Schools: HEC '15 (A)
GMAT 1: 690 Q47 V38
GMAT ToolKit User
Re: 3x^2 + 2x - 8 =  [#permalink]

Show Tags

New post 14 May 2012, 01:05
1
3x^2 + 2x - 8

X1*X2=-8/3
X1+X2=-2/3

Only option B satisfies these parameters
_________________
Happy are those who dream dreams and are ready to pay the price to make them come true

I am still on all gmat forums. msg me if you want to ask me smth
Senior Manager
Senior Manager
User avatar
Joined: 12 Aug 2015
Posts: 280
Concentration: General Management, Operations
GMAT 1: 640 Q40 V37
GMAT 2: 650 Q43 V36
GMAT 3: 600 Q47 V27
GPA: 3.3
WE: Management Consulting (Consulting)
3x^2 + 2x - 8 =  [#permalink]

Show Tags

New post 21 Jan 2016, 07:11
1
1. just open the brackets. A is out, B is in. 30 secs.

2. factoring box

a. 3x^2 + 2x - 8 -> mulptiply a and c = 3*-8 = -24
b. factors of -24 that add up to b (i.e. 2) are 6 and -4 (note that the larger factor should be positive because b is positive, one of the factors is negative)
c. arrange the box as below and find common factors in the 2 vertical and 2 horizontal lines. form equation. of (3x-4)(x+2)
Attachments

box.jpg
box.jpg [ 7.22 KiB | Viewed 3778 times ]

Intern
Intern
avatar
B
Joined: 15 Feb 2019
Posts: 15
Re: 3x^2 + 2x - 8 =  [#permalink]

Show Tags

New post 04 Apr 2019, 06:22
I used quadratic equation in solving this
3x^2+2x-8=
X=-b+/- sqrt b^2-4ac/2a
Where a =3, b=2, And c=-8
X=-2+/-sqrt 2^2-4(3)(-8)/2(3)
X=-2+/-sqrt 4+96/6
X=-2+/-sqrt100/6=-2+/-10/6
X=-2+10/6 or X=-2-10/6
X=8/6=4/3 or X=-12/6=-2
Therefore X=4/3 or -2
X=4/3= 3x=4, 3x-4=0
X=-2, X+2=0
So we have 3x-4=0 or x+2=0
Final answer (3x-4)(x+2)
Answer is B

Posted from my mobile device
Intern
Intern
avatar
B
Joined: 15 Feb 2019
Posts: 15
Re: 3x^2 + 2x - 8 =  [#permalink]

Show Tags

New post 04 Apr 2019, 06:27
1
I used quadratic equation in solving this
3x^2+2x-8=
X=-b+/- sqrt b^2-4ac/2a
Where a =3, b=2, And c=-8
X=-2+/-sqrt 2^2-4(3)(-8)/2(3)
X=-2+/-sqrt 4+96/6
X=-2+/-sqrt100/6=-2+/-10/6
X=-2+10/6 or X=-2-10/6
X=8/6=4/3 or X=-12/6=-2
Therefore X=4/3 or -2
X=4/3= 3x=4, 3x-4=0
X=-2, X+2=0
So we have 3x-4=0 or x+2=0
Final answer (3x-4)(x+2)
Answer is B

Posted from my mobile device
Attachments

20190404_142712.jpg
20190404_142712.jpg [ 937.92 KiB | Viewed 593 times ]

Target Test Prep Representative
User avatar
V
Status: Founder & CEO
Affiliations: Target Test Prep
Joined: 14 Oct 2015
Posts: 8699
Location: United States (CA)
Re: 3x^2 + 2x - 8 =  [#permalink]

Show Tags

New post 07 Apr 2019, 18:43
1
malkov wrote:
3x^2 + 2x - 8 =

A. (3x-4)(x-2)
B. (3x-4)(x+2)
C. (3x-4)(x-2)
D. (3x-2)(x+4)
E. none of above


Factoring the given quadratic expression, we have:

(3x - 4)(x + 2)

Answer: B
_________________

Scott Woodbury-Stewart

Founder and CEO

Scott@TargetTestPrep.com
TTP - Target Test Prep Logo
122 Reviews

5-star rated online GMAT quant
self study course

See why Target Test Prep is the top rated GMAT quant course on GMAT Club. Read Our Reviews

If you find one of my posts helpful, please take a moment to click on the "Kudos" button.

GMAT Club Bot
Re: 3x^2 + 2x - 8 =   [#permalink] 07 Apr 2019, 18:43
Display posts from previous: Sort by

3x^2 + 2x - 8 =

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





Powered by phpBB © phpBB Group | Emoji artwork provided by EmojiOne