Find all School-related info fast with the new School-Specific MBA Forum

It is currently 22 May 2013, 06:08
Customize  |  Hide

Does the equation y = (x – p)(x – q) intercept the x-axis at

  Question banks Downloads My Bookmarks Reviews  
Author Message
TAGS:
Manager
Manager
Joined: 22 Apr 2011
Posts: 225
Schools: Mccombs business school, Mays business school, Rotman Business School,
Followers: 0

Kudos [?]: 10 [0], given: 18

Does the equation y = (x – p)(x – q) intercept the x-axis at [#permalink] New post 09 Jun 2012, 17:24
00:00

Question Stats:

80% (02:31) correct 20% (00:39) wrong based on 2 sessions
Does the equation y = (x – p)(x – q) intercept the x-axis at the point (2,0)?

(1) pq = -8

(2) -2 – p = q
[Reveal] Spoiler: OA

_________________

some people are successful, because they have been fortunate enough and some people earn success, because they have been determined.....

please press kudos if you like my post.... i am begging for kudos...lol

Senior Manager
Senior Manager
User avatar
Joined: 13 Jan 2012
Posts: 271
Weight: 170lbs
WE: Analyst (Other)
Followers: 4

Kudos [?]: 50 [0], given: 28

CAT Tests
Re: coordinate [#permalink] New post 09 Jun 2012, 18:19
y=(x-p)(x-q)

Basically, when y=0 and x=2, does equation balance?

0 = (2-p)(2-q)
0 = 4-2q-2p+qp

In order to know this, we need to know q & p

1) pq = -8
This only tell us p or q, but not both.

[strike]AD[/strike]
BCE

2) -2 - p = q
This only tell us p or q, but not both.

1+2) We can determine both p & q through these two independent equations.

Answer is C.
GMAT Club team member
User avatar
Joined: 02 Sep 2009
Posts: 11563
Followers: 1795

Kudos [?]: 9570 [0], given: 826

Re: Does the equation y = (x – p)(x – q) intercept the x-axis at [#permalink] New post 10 Jun 2012, 02:13
Does the equation y = (x – p)(x – q) intercept the x-axis at the point (2,0)?

x-intercepts of the graph y=(x-p)(x-q) is the values of x for which (x-p)(x-q)=0. So, the x-intercepts are (p, 0) and (q, 0). The question basically asks whether either p or q equals 2.

(1) pq = -8. Not sufficient to say whether p or q equals 2.

(2) -2 – p = q. Not sufficient to say whether p or q equals 2.

(1)+(2) Solving pq=-8 and -2-p=q gives us that either p=-4 and q=2 OR p=2 and q=-4. In ether case one of the unknowns is 2, so y=(x-p)(x-q) intercepts the x-axis at the point (2,0). Sufficient.

Answer: C.

Hope it's clear.
_________________

PLEASE READ AND FOLLOW: 11 Rules for Posting!!!

RESOURCES: [GMAT MATH BOOK]; 1. Triangles; 2. Polygons; 3. Coordinate Geometry; 4. Factorials; 5. Circles; 6. Number Theory

COLLECTION OF QUESTIONS:
PS: 1. Tough and Tricky questions; 2. Hard questions; 3. Hard questions part 2; 4. Standard deviation; 5. Tough Problem Solving Questions With Solutions; 6. Probability and Combinations Questions With Solutions; 7 Tough and tricky exponents and roots questions; 8 12 Easy Pieces (or not?); 9 Bakers' Dozen; 10 Algebra set. NEW!!!

DS: 1. DS tough questions; 2. DS tough questions part 2; 3. DS tough questions part 3; 4. DS Standard deviation; 5. Inequalities; 6. 700+ GMAT Data Sufficiency Questions With Explanations; 7 Tough and tricky exponents and roots questions; 8 The Discreet Charm of the DS ; 9 Devil's Dozen!!!; 10 Number Properties set. NEW!!!


What are GMAT Club Tests?
25 extra-hard Quant Tests

Find out what's new at GMAT Club - latest features and updates

Senior Manager
Senior Manager
User avatar
Joined: 13 Jan 2012
Posts: 271
Weight: 170lbs
WE: Analyst (Other)
Followers: 4

Kudos [?]: 50 [0], given: 28

CAT Tests
Re: Does the equation y = (x – p)(x – q) intercept the x-axis at [#permalink] New post 10 Jun 2012, 02:15
Bunuel wrote:
Does the equation y = (x – p)(x – q) intercept the x-axis at the point (2,0)?

x-intercepts of the graph y=(x-p)(x-q) is the values of x for which (x-p)(x-q)=0. So, the x-intercepts are (p, 0) and (q, 0). The question basically asks whether either p or q equals 2.

(1) pq = -8. Not sufficient to say whether p or q equals 2.

(2) -2 – p = q. Not sufficient to say whether p or q equals 2.

(1)+(2) Solving pq=-8 and -2-p=q gives us that either p=-4 and q=2 OR p=2 and q=-4. In ether case one of the unknowns is 2, so y=(x-p)(x-q) intercepts the x-axis at the point (2,0). Sufficient.

Answer: C.

Hope it's clear.


Damn, you're good! Was my approach right at all? Sometimes I wish a had an identical twin who could just get a 50 on my Quant section for me while I do the Verbal section, haha.
Intern
Intern
Joined: 28 Dec 2012
Posts: 46
Schools: LBS '14
Followers: 1

Kudos [?]: 11 [0], given: 53

Does the equation y = (x – p)(x – q) intercept the x-axis at the [#permalink] New post 13 Jan 2013, 12:30
C.

If y = 0,

this reduces to a quadratic equation.
sum of roots = 2, product of roots = -8.
Thus the roots are 4 and -2.
Line passes through (4,0) and (-2,0)
Hence the answer is NO
Does the equation y = (x – p)(x – q) intercept the x-axis at the   [#permalink] 13 Jan 2013, 12:30
    Similar topics Author Replies Last post
Similar
Topics:
New posts If 2 + i sqrt3 is a root of the equation x^2 + px + q = 0, sunniboy007 1 01 Mar 2004, 16:12
New posts A,B are roots of equation (x)(x)-px+q=0. A,C are roots of smcgrath12 3 30 Oct 2004, 13:11
New posts (M) Does the equation y = (x p)(x q) intercept the x-axis at banksy 3 17 Mar 2011, 14:45
New posts 4 A line with the equation y = px + q is reflected over the bhandariavi 8 20 Mar 2011, 17:14
New posts 2 A line with the equation y = px + q is reflected over the li sanjoo 4 02 Oct 2012, 01:19
Display posts from previous: Sort by

Does the equation y = (x – p)(x – q) intercept the x-axis at

  Question banks Downloads My Bookmarks Reviews  


GMAT Club MBA Forum Home| About| Privacy Policy| Terms and Conditions| GMAT Club Rules| Contact| Sitemap

Powered by phpBB © phpBB Group and phpBB SEO

Kindly note that the GMAT® test is a registered trademark of the Graduate Management Admission Council®, and this site has neither been reviewed nor endorsed by GMAC®.