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

 It is currently 18 Oct 2019, 21:37

### 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 2x + 3 = y + 1/y, then x + y = (1) x = –1/4 (2) y = 2

Author Message
TAGS:

### Hide Tags

Senior RC Moderator
Joined: 02 Nov 2016
Posts: 4118
GPA: 3.39
If 2x + 3 = y + 1/y, then x + y = (1) x = –1/4 (2) y = 2  [#permalink]

### Show Tags

21 Sep 2019, 23:54
00:00

Difficulty:

35% (medium)

Question Stats:

57% (01:54) correct 43% (01:16) wrong based on 20 sessions

### HideShow timer Statistics

If $$2x + 3 = y + \frac{1}{y,}$$ then $$x + y =$$

(1) $$x = –\frac{1}{4}$$

(2) $$y = 2$$

Source: Nova GMAT

_________________
Math Expert
Joined: 02 Aug 2009
Posts: 7981
If 2x + 3 = y + 1/y, then x + y = (1) x = –1/4 (2) y = 2  [#permalink]

### Show Tags

22 Sep 2019, 19:27
1
If $$2x + 3 = y + \frac{1}{y,}$$ then $$x + y =$$

If you are short of time, we have one equation given, we require one more equation to answer..
If we know the value of y, we can find x, as x does not have any power. However if we know the value of x, there is a likelihood that we do not get the answer, as we will have a quadratic equation with y^2, so y could have two values...
Short of time, mark B without solving

(1) $$x = –\frac{1}{4}$$
$$2x + 3 = y + \frac{1}{y}$$=$$2*-(\frac{1}{4}) + 3 = y + \frac{1}{y}$$=$$\frac{5}{2} = y + \frac{1}{y}$$..
$$2y^2-5y+2=0.....2y(y-2)-(y-2)=0....(2y-1)(y-2)=0$$, so y could be 2 or 1/2
Insuff

(2) $$y = 2$$
$$2x + 3 = y + \frac{1}{y,}$$=$$2x + 3 = 2+ \frac{1}{2}=\frac{5}{2}...2x=\frac{-1}{2}...x=\frac{-1}{4}$$
Thus, $$x+y=2+(\frac{-1}{4})=\frac{7}{4}$$
Suff

B
_________________
If 2x + 3 = y + 1/y, then x + y = (1) x = –1/4 (2) y = 2   [#permalink] 22 Sep 2019, 19:27
Display posts from previous: Sort by