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

It is currently 19 Oct 2019, 02:42

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

Which of the following is a solution for 2x^2 + x − 2 = 1?

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

Hide Tags

Find Similar Topics 
Math Expert
User avatar
V
Joined: 02 Sep 2009
Posts: 58452
Which of the following is a solution for 2x^2 + x − 2 = 1?  [#permalink]

Show Tags

New post 19 Feb 2017, 10:10
00:00
A
B
C
D
E

Difficulty:

  25% (medium)

Question Stats:

78% (01:13) correct 22% (01:34) wrong based on 188 sessions

HideShow timer Statistics

e-GMAT Representative
User avatar
V
Joined: 04 Jan 2015
Posts: 3074
Re: Which of the following is a solution for 2x^2 + x − 2 = 1?  [#permalink]

Show Tags

New post 19 Feb 2017, 10:39
Bunuel wrote:
Which of the following is a solution for 2x^2 + x − 2 = 1?

A. −6
B. −1
C. 1
D. 3/2
E. 3



Hey,

PFB the solution.

    \(2x^2 + x - 2 = 1\)

The above equation can be written as -

    \(2x^2 + x -2 -1 = 0\)
    \(2x^2 + x - 3 = 0\)
    \(2x^2 + 3x - 2x - 3 = 0\)
    \(x( 2x + 3) -1 (2x +3) = 0\)
    \((x - 1) (2x + 3) = 0\)

Therefore either \(x-1 = 0\) which gives \(x =1\) or
\(2x +3 = 0\), which gives \(x = -\frac{3}{2}\)

Since the question asks us, which of the following could be a solution of \(x\), we can confidently say that the answer will be 1, Option C

Thanks,
Saquib
Quant Expert
e-GMAT

Register for our Free Session on Number Properties (held every 3rd week) to solve exciting 700+ Level Questions in a classroom environment under the real-time guidance of our Experts :)

Image
_________________
Intern
Intern
avatar
B
Joined: 07 Apr 2015
Posts: 10
Re: Which of the following is a solution for 2x^2 + x − 2 = 1?  [#permalink]

Show Tags

New post 19 Feb 2017, 10:41
Move the terms to the left side and set equal to zero------->2x^2+x-3=0

Backsolve for quick solution.

C. 1------>2(1)^2+1-3=0--->2(1)-2=0---->2=2

Answer C.
e-GMAT Representative
User avatar
V
Joined: 04 Jan 2015
Posts: 3074
Re: Which of the following is a solution for 2x^2 + x − 2 = 1?  [#permalink]

Show Tags

New post 19 Feb 2017, 10:47
2
For someone who is not comfortable with Quadratic Equations and forming factors, an easy way out would be to use the answer options to get the answer. :)

2x^2 + x -2 = 1

A. \(2(-6)^2 + (-6) - 2\) is not equal to \(1\)
B. \(2(-1)^2 + (-1) - 2\) is not equal to \(1\)
C. \(2(1)^2 + (1) - 2\) is equal to \(1\)
D. \(2(3/2)^2 + (3/2) - 2\) is not equal to \(1\)
E. \(2(3)^2 + (3) - 2\) is not equal to \(1\)

Hence Option C is the correct answer.

Note : Once you confirm that Option C gives us 1, we do not need to check Option D and E. :)

Thanks,
Saquib
Quant Expert
e-GMAT

Register for our Free Session on Number Properties (held every 3rd week) to solve exciting 700+ Level Questions in a classroom environment under the real-time guidance of our Experts :)

Image
_________________
Intern
Intern
User avatar
Joined: 06 Oct 2016
Posts: 4
Location: Germany
Re: Which of the following is a solution for 2x^2 + x − 2 = 1?  [#permalink]

Show Tags

New post 21 Apr 2017, 02:54
2x2+x−2−1=02x2+x−2−1=0
2x2+x−3=02x2+x−3=0
2x2+3x−2x−3=02x2+3x−2x−3=0
x(2x+3)−1(2x+3)=0x(2x+3)−1(2x+3)=0
(x−1)(2x+3)=0(x−1)(2x+3)=0
x−1=0x−1=0
x=1

Ans:-C
Target Test Prep Representative
User avatar
G
Status: Head GMAT Instructor
Affiliations: Target Test Prep
Joined: 04 Mar 2011
Posts: 2815
Re: Which of the following is a solution for 2x^2 + x − 2 = 1?  [#permalink]

Show Tags

New post 25 Apr 2017, 07:54
Bunuel wrote:
Which of the following is a solution for 2x^2 + x − 2 = 1?

A. −6
B. −1
C. 1
D. 3/2
E. 3


Let’s simplify the given equation:

2x^2 + x − 2 = 1

2x^2 + x − 3 = 0

(2x + 3)(x − 1) = 0

2x + 3 = 0

2x = -3

x = -3/2

OR

x - 1 = 0

x = 1

Answer: C
_________________

Jeffrey Miller

Head of GMAT Instruction

Jeff@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.

VP
VP
User avatar
D
Joined: 09 Mar 2016
Posts: 1230
Re: Which of the following is a solution for 2x^2 + x − 2 = 1?  [#permalink]

Show Tags

New post 01 Nov 2018, 13:58
Bunuel wrote:
Which of the following is a solution for 2x^2 + x − 2 = 1?

A. −6
B. −1
C. 1
D. 3/2
E. 3


\(2x^2 + x − 2 = 1\)

\(2x^2 + x − 2 − 1 = 0\)

\(2x^2 + x − 3 = 0\)

now all i have to do now is test values

clearly only 1 yields 0

\(2 *1^2 + 1 − 3 = 0\)

\(3-3=0\)
Senior Manager
Senior Manager
User avatar
S
Joined: 12 Sep 2017
Posts: 302
Re: Which of the following is a solution for 2x^2 + x − 2 = 1?  [#permalink]

Show Tags

New post 16 Jan 2019, 20:43
EgmatQuantExpert wrote:
Bunuel wrote:
Which of the following is a solution for 2x^2 + x − 2 = 1?

A. −6
B. −1
C. 1
D. 3/2
E. 3



Hey,

PFB the solution.

    \(2x^2 + x - 2 = 1\)

The above equation can be written as -

    \(2x^2 + x -2 -1 = 0\)
    \(2x^2 + x - 3 = 0\)
    \(2x^2 + 3x - 2x - 3 = 0\)
    \(x( 2x + 3) -1 (2x +3) = 0\)
    \((x - 1) (2x + 3) = 0\)

Therefore either \(x-1 = 0\) which gives \(x =1\) or
\(2x +3 = 0\), which gives \(x = -\frac{3}{2}\)

Since the question asks us, which of the following could be a solution of \(x\), we can confidently say that the answer will be 1, Option C

Thanks,
Saquib
Quant Expert
e-GMAT

Register for our Free Session on Number Properties (held every 3rd week) to solve exciting 700+ Level Questions in a classroom environment under the real-time guidance of our Experts :)

Image


Hello!

Does anyone know which is the basic theory to know how to solve this kind of QE?

    \(2x^2 + x -2 -1 = 0\)
    \(2x^2 + x - 3 = 0\)
    \(2x^2 + 3x - 2x - 3 = 0\)
    \(x( 2x + 3) -1 (2x +3) = 0\)
    \((x - 1) (2x + 3) = 0\)

Kind regards!
GMAT Club Bot
Re: Which of the following is a solution for 2x^2 + x − 2 = 1?   [#permalink] 16 Jan 2019, 20:43
Display posts from previous: Sort by

Which of the following is a solution for 2x^2 + x − 2 = 1?

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





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