In the xy plane, at what two points does the graph of : DS Archive
Check GMAT Club App Tracker for the Latest School Decision Releases http://gmatclub.com/AppTrack

 It is currently 07 Dec 2016, 10:44

Help Desk is Open: Join Chat Room1 to Discuss your Queries with MBA Expert |  Join Chat Room2 for Chicago-Booth Decision Updates

### 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

# Events & Promotions

###### Events & Promotions in June
Open Detailed Calendar

# In the xy plane, at what two points does the graph of

Author Message
Manager
Joined: 08 Jan 2007
Posts: 67
Location: D.C.
Followers: 1

Kudos [?]: 1 [0], given: 0

In the xy plane, at what two points does the graph of [#permalink]

### Show Tags

07 Aug 2007, 02:39
00:00

Difficulty:

(N/A)

Question Stats:

0% (00:00) correct 0% (00:00) wrong based on 0 sessions

### HideShow timer Statistics

This topic is locked. If you want to discuss this question please re-post it in the respective forum.

In the xy plane, at what two points does the graph of y=(x+a)(x+b) intersect the x-axis?

1 - a + b = -1

2 - The graph intersects the y-axis at (0,-6)

this is a GMATPrep question
Director
Joined: 12 Jul 2007
Posts: 862
Followers: 15

Kudos [?]: 280 [0], given: 0

### Show Tags

07 Aug 2007, 03:26
I'm thinking C for this one.

1. a + b = -1 this could be any two numbers with a sum of -1 now. insufficient

2. The graph intersects the y-axis at (0, -6). so plug 0 in for X in this equation:

y = x^2 + xb + xa + ab

and you're left with y = ab = -6. now this taken on it's own could be any two numbers with -6 as the product (1, -6) or (2, -3) etc. insufficient as well

taken on their own they aren't much help, but when taken together you know that the sum of A and B is -1 and the product is -6. The only two numbers that work now are -3 and 2.

anyone agree with this one?
Senior Manager
Joined: 24 Nov 2006
Posts: 350
Followers: 1

Kudos [?]: 23 [0], given: 0

### Show Tags

07 Aug 2007, 14:00
VAGMAT wrote:
In the xy plane, at what two points does the graph of y=(x+a)(x+b) intersect the x-axis?

1 - a + b = -1

2 - The graph intersects the y-axis at (0,-6)

The question can be understood as: what are a and b? (a and b are the intersects of the function with the x axis).

(1) Insuff.
(2) Same.

(12) a = 0; then b = -1. Suff. C.
VP
Joined: 10 Jun 2007
Posts: 1459
Followers: 7

Kudos [?]: 251 [0], given: 0

### Show Tags

07 Aug 2007, 15:00
VAGMAT wrote:
In the xy plane, at what two points does the graph of y=(x+a)(x+b) intersect the x-axis?

1 - a + b = -1

2 - The graph intersects the y-axis at (0,-6)

this is a GMATPrep question

Got C too.
From the question, we know that the two values that we need to find are a and b.
(1) -a+b = 1, doesn't tell much. INSUFFICIENT.
(2) plug in x=0, you have -6 = a*b
INSUFFICIENT.

Together, two equations, two unknowns. SUFFICIENT.
Manager
Joined: 22 May 2006
Posts: 184
Followers: 1

Kudos [?]: 13 [0], given: 0

### Show Tags

08 Aug 2007, 03:34
I am not able to solve for a2-2a+6, which is the equation I get. It gives a complex number. In such a case can we say that it is not sufficient and go for E?
Display posts from previous: Sort by

# In the xy plane, at what two points does the graph of

 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®.