It is currently 12 Nov 2019, 10:08
My 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.

If x > 0 and 2x2 + 6x = 8, then the average (arithmetic mean

  Question banks Downloads My Bookmarks Reviews Important topics  
Author Message
TAGS:
Founder
Founder
User avatar
Joined: 18 Apr 2015
Posts: 8729
Followers: 175

Kudos [?]: 2012 [0], given: 8049

CAT Tests
If x > 0 and 2x2 + 6x = 8, then the average (arithmetic mean [#permalink] New post 22 Oct 2018, 03:58
Expert's post
00:00

Question Stats:

82% (01:05) correct 17% (01:06) wrong based on 28 sessions
If \(x > 0\) and \(2x^2 + 6x = 8\), then the average (arithmetic mean) of x + 2, 2x – 1, and x + 4 is equal to which of the following?

A. –2

B. 3

C. 3.5

D. 5

E. 7
[Reveal] Spoiler: OA

_________________

Need Practice? 20 Free GRE Quant Tests available for free with 20 Kudos
GRE Prep Club Members of the Month: Each member of the month will get three months free access of GRE Prep Club tests.

GRE Instructor
User avatar
Joined: 10 Apr 2015
Posts: 2548
Followers: 90

Kudos [?]: 2709 [0], given: 39

CAT Tests
Re: If x > 0 and 2x2 + 6x = 8, then the average (arithmetic mean [#permalink] New post 22 Oct 2018, 09:06
Expert's post
Carcass Array[WROTE]:
If \(x > 0\) and \(2x^2 + 6x = 8\), then the average (arithmetic mean) of x + 2, 2x – 1, and x + 4 is equal to which of the following?

A. –2

B. 3

C. 3.5

D. 5

E. 7


Given: 2x² + 6x = 8
Divide both sides by 2 to get: x² + 3x = 4
Subtract 4 from both sides to get: x² + 3x - 4 = 0
Factor: (x + 4)(x - 1) = 0
Solved to get: EITHER x = -4 OR x = 1

Since we're told that x > 0, we can be certain that x = 1

QUESTION: What is the average (arithmetic mean) of x + 2, 2x – 1, and x + 4?
If x = 1, then:
x + 2 = 1 + 2 = 3
2x - 1 = 2(1) - 1 = 1
x + 4 = 1 + 4 = 5

Average of 3, 1 and 5 = (3 + 1 + 5)/3
= 9/3
= 3

Answer: B

RELATED VIDEO FROM OUR COURSE

_________________

Brent Hanneson – Creator of greenlighttestprep.com
Image
Sign up for my free GRE Question of the Day emails

Re: If x > 0 and 2x2 + 6x = 8, then the average (arithmetic mean   [#permalink] 22 Oct 2018, 09:06
Display posts from previous: Sort by

If x > 0 and 2x2 + 6x = 8, then the average (arithmetic mean

  Question banks Downloads My Bookmarks Reviews Important topics  


GRE Prep Club Forum Home| About| Terms and Conditions and Privacy Policy| GRE Prep Club Rules| Contact

Powered by phpBB © phpBB Group

Kindly note that the GRE® test is a registered trademark of the Educational Testing Service®, and this site has neither been reviewed nor endorsed by ETS®.