Welcome to Beat The GMAT, the world's largest GMAT & MBA forum. Please join our rich community of friendly members. Get free help from
experts who teach at the leading GMAT & MBA prep companies — Kaplan, Veritas Prep, Manhattan GMAT and Stacy Blackman Consulting.

Announcement: Apply for the Fall 2008 Beat The GMAT Scholarship, featuring $20,000 in prizes.

gmat prep question


 
Post new topic   Reply to topic    Beat The GMAT Forum Index -> GMAT Math
View previous topic :: View next topic  
Author Message
jamesk486
Really wants to Beat The GMAT!


Joined: 28 Mar 2007
Posts: 106

Thanks given: 0
Thanked 0 times in 0 posts
PostPosted: Fri May 11, 2007 7:36 am    Post subject: gmat prep question Reply with quote
In the xy plane, at what two points does the graph of y= (x+a)(x+b)
(1) a+b=-1
(2) the graph intersects the x=axis at at (0,6)

can someone pls pls help me out?
Back to top


View user's profile Send private message
jayhawk2001
Moderator


Joined: 28 Jan 2007
Posts: 789

Thanks given: 0
Thanked 11 times in 11 posts

Location: Silicon valley, California
PostPosted: Fri May 11, 2007 2:58 pm    Post subject: Re: gmat prep question Reply with quote
jamesk486 wrote:
In the xy plane, at what two points does the graph of y= (x+a)(x+b)
(1) a+b=-1
(2) the graph intersects the x=axis at at (0,6)

can someone pls pls help me out?


Is statement (2) given correctly. I can't visualize a graph
cutting the x-axis at (0,6). If a graph cuts the x-axis, the y intercept
has to be zero. In this case, y = 6 ??

I recall seeing this question on gmat-prep when I took the test and if
I recall correctly, it was something along the lines of

1 - insufficient. We just know a+b=-1. We need to find a and b since
these are the 2 points at which the graph cuts the x-axis

2 - insufficient. We just know ab=6 (substitute for x, y in eqn)

Together we can find a and b and hence is sufficient.

Answer is C.
Back to top


View user's profile Send private message
Display posts from previous:   
Post new topic   Reply to topic    Beat The GMAT Forum Index -> GMAT Math All times are GMT - 7 Hours
Page 1 of 1

 
Jump to:  
You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot vote in polls in this forum
You cannot attach files in this forum
You cannot download files in this forum



"GMAT" and other GMAC™ trademarks are registered trademarks of the Graduate Management Admission Council™. The Graduate Management Admission Council™ does not endorse, nor is it affiliated in any way with the owner or any content on this website. The opinions expressed here are solely those of the author or those of the members of this website. Copyright © 2008 BTG Test Prep, LLC. Powered by phpBB © 2001, 2005 phpBB Group.