 It is currently 26 Sep 2020, 00:47 ### 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

#### Not interested in getting valuable practice questions and articles delivered to your email? No problem, unsubscribe here. # y=2x^2 + 7x -3  Question banks Downloads My Bookmarks Reviews Important topics
Author Message
TAGS:
Founder  Joined: 18 Apr 2015
Posts: 13362
Followers: 289

Kudos [?]: 3396 , given: 12202

Expert's post 00:00

Question Stats: 82% (00:52) correct 17% (01:02) wrong based on 218 sessions
$$y= 2x^2 + 7x - 3$$

 Quantity A Quantity B $$x$$ $$y$$

A)The quantity in Column A is greater.
B)The quantity in Column B is greater.
C)The two quantities are equal.
D)The relationship cannot be determined from the information given.

Practice Questions
Question: 5
Page: 112
Difficulty: medium
[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.

Founder  Joined: 18 Apr 2015
Posts: 13362
Followers: 289

Kudos [?]: 3396 , given: 12202

Re: y=2x^2 + 7x -3 [#permalink]
Expert's post
Explanation

If x = 0 then y = 2($$0^2$$) + 7(0) -3= -3 so in this case, x > y ; but if x = 1 then y = 2($$2^1$$) + 7(1) -3 = 6, so in this case , y > x.
Thus, the correct answer is Choice D, the relationship cannot be determined from the information given.
_________________

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. Intern Joined: 02 Aug 2017
Posts: 24
Followers: 1

Kudos [?]: 15  , given: 4

Re: y=2x^2 + 7x -3 [#permalink]
1
KUDOS
fact is y= 2x^2 + 7x -3

plugging in values
when x=0, y=-3 ==> x>y
when x=1, y=6==> x<y

here relationship varies, so ans iS D. GRE Instructor Joined: 10 Apr 2015
Posts: 3835
Followers: 148

Kudos [?]: 4491  , given: 69

Re: y=2x^2 + 7x -3 [#permalink]
1
KUDOS
Expert's post
Carcass wrote:
$$y= 2x^2 + 7x - 3$$

 Quantity A Quantity B $$x$$ $$y$$

Let's test some values.

Case i: x = 0
Plug x = 0 into the given equation to get: y = 2(0)² + 7(0) - 3
Simplify to get to get: y = -3

We get:
QUANTITY A: 0
QUANTITY B: -3
In this case, Quantity A is greater than Quantity B

Case ii: x = 1
Plug x = 1 into the given equation to get: y = 2(1)² + 7(1) - 3
Simplify to get to get: y = 6

We get:
QUANTITY A: 1
QUANTITY B: 6
In this case, Quantity B is greater than Quantity A

RELATED VIDEO FROM MY COURSE

_________________

Brent Hanneson – Creator of greenlighttestprep.com
If you enjoy my solutions, you'll like my GRE prep course. Intern Joined: 12 Sep 2018
Posts: 12
Followers: 0

Kudos [?]: 2 , given: 3

Re: y=2x^2 + 7x -3 [#permalink]
Carcass wrote:
$$y= 2x^2 + 7x - 3$$

 Quantity A Quantity B $$x$$ $$y$$

A)The quantity in Column A is greater.
B)The quantity in Column B is greater.
C)The two quantities are equal.
D)The relationship cannot be determined from the information given.

Practice Questions
Question: 5
Page: 112
Difficulty: medium

Do we take out the roots of X only when the equation is equal to 0 rather than y?
Founder  Joined: 18 Apr 2015
Posts: 13362
Followers: 289

Kudos [?]: 3396 , given: 12202

Re: y=2x^2 + 7x -3 [#permalink]
Expert's post
Is the same. Actually, y is a number
_________________

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 Joined: 10 Apr 2015
Posts: 3835
Followers: 148

Kudos [?]: 4491  , given: 69

Re: y=2x^2 + 7x -3 [#permalink]
2
KUDOS
Expert's post
Rocko911 wrote:
Carcass wrote:
$$y= 2x^2 + 7x - 3$$

 Quantity A Quantity B $$x$$ $$y$$

A)The quantity in Column A is greater.
B)The quantity in Column B is greater.
C)The two quantities are equal.
D)The relationship cannot be determined from the information given.

Practice Questions
Question: 5
Page: 112
Difficulty: medium

Do we take out the roots of X only when the equation is equal to 0 rather than y?

A lot of students will automatically want to take $$y= 2x^2 + 7x - 3$$ and convert it to the equation $$0= 2x^2 + 7x - 3$$, however, we've now removed an entire variable (y) from the equation, which makes no sense.

Here's an analogous example: If we have the equation y = x - 2, there are infinitely-many solutions including, x = 0 & y = -2, and x = 2 & y = 0, and x = 5 & y = 3, and x = 10 & y = 8, and . . .

If we magically turn the y into a 0, we get: 0 = x - 2, which means x = 2 (what about y?)

As you can see, turning the equation $$y= 2x^2 + 7x - 3$$ into the equation $$0= 2x^2 + 7x - 3$$ creates a totally different equation.

Cheers,
Brent
_________________

Brent Hanneson – Creator of greenlighttestprep.com
If you enjoy my solutions, you'll like my GRE prep course.  Re: y=2x^2 + 7x -3   [#permalink] 14 Jul 2019, 06:59
Display posts from previous: Sort by

# y=2x^2 + 7x -3  Question banks Downloads My Bookmarks Reviews Important topics 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®.