It is currently 18 Feb 2019, 02:52

### 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

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

# If (6 + 2/x)(x - 4) = 0, and x does not equal 4, then x =

Author Message
TAGS:
Senior Manager
Joined: 20 May 2014
Posts: 282
Followers: 18

Kudos [?]: 50 [0], given: 220

If (6 + 2/x)(x - 4) = 0, and x does not equal 4, then x = [#permalink]  18 Oct 2017, 22:48
00:00

Question Stats:

100% (05:03) correct 0% (00:00) wrong based on 1 sessions
If $$(6 + \frac{2}{x})(x - 4) = 0$$, and x does not equal 4, then x =

(A) -6
(B) -4
(C) -1/3
(D) 1/3
(E) 3

Kudos for correct solution.
[Reveal] Spoiler: OA
Director
Joined: 03 Sep 2017
Posts: 521
Followers: 1

Kudos [?]: 343 [0], given: 66

Re: If (6 + 2/x)(x - 4) = 0, and x does not equal 4, then x = [#permalink]  19 Oct 2017, 00:28
Multiplying the two expressions in parenthesis we get $$6x-24-2-\frac{8}{x}=0$$. This can be rewritten as $$6x^2-22x-8=0$$. Solving it we get two solutions $$x = 4$$ and $$x = -\frac{1}{3}$$. Given that x cannot be equal to 4 the solution is the other one, answer C
Director
Joined: 20 Apr 2016
Posts: 816
WE: Engineering (Energy and Utilities)
Followers: 9

Kudos [?]: 587 [0], given: 113

Re: If (6 + 2/x)(x - 4) = 0, and x does not equal 4, then x = [#permalink]  19 Oct 2017, 01:18
Bunuel wrote:
If $$(6 + \frac{2}{x})(x - 4) = 0$$, and x does not equal 4, then x =

(A) -6
(B) -4
(C) -1/3
(D) 1/3
(E) 3

Kudos for correct solution.

$$(6 + \frac{2}{x})(x - 4) = 0$$

or we can write as = 6x^2 - 22x - 8 =0

or 3x^2 -11x - 4 = 0 (dividing by 2) which is in the form ax^2 + bx + c

Now we need the value of x , the best way in the complex equation is to use the formula, which I prefer

x= $$(-b +- \sqrt{(b^2-4*a*c)}) /2*a$$

x= $$(-11 +- \sqrt{169}) / 6$$ (where a= 3, b= -11 c = -4)

or x = $$\frac{(11+- 13)}{6}$$

Now taking positive value
x= $$\frac{(11+13)}{6}$$ = 4

Taking negative value

x= $$\frac{(11-13)}{6}$$ = $$-\frac{1}{3}$$

Since x= 4 is not possible, therefore x = $$-\frac{1}{3}$$
_________________

If you found this post useful, please let me know by pressing the Kudos Button

Rules for Posting https://greprepclub.com/forum/rules-for ... -1083.html

Re: If (6 + 2/x)(x - 4) = 0, and x does not equal 4, then x =   [#permalink] 19 Oct 2017, 01:18
Display posts from previous: Sort by