BREAKING: Target Test Prep releases Brand New 2026 On Demand GMAT prep course

Redeem

quadratic equation

This topic has expert replies
Post new topic Post Reply
Previous Topic Next Topic
User avatar
Master | Next Rank: 500 Posts
Posts: 212
Joined: Sat Dec 01, 2007 4:19 pm
Thanked: 5 times

quadratic equation

by vscid » Sun Mar 14, 2010 8:05 am
If 6xy = x^2y + 9y, what is the value of xy?

(1) x = -2

(2) x < 0
The GMAT is indeed adaptable. Whenever I answer RC, it proficiently 'adapts' itself to mark my 'right' answer 'wrong'.
Top
Source: — Data Sufficiency |
User avatar
Community Manager
Posts: 1537
Joined: Mon Aug 10, 2009 6:10 pm
Thanked: 653 times
Followed by:252 members

by papgust » Sun Mar 14, 2010 8:27 am
https://www.beatthegmat.com/mgmat-ds-t15290.html
Top
Master | Next Rank: 500 Posts
Posts: 232
Joined: Sun Feb 28, 2010 10:47 pm
Thanked: 10 times

by Phirozz » Sun Mar 14, 2010 8:53 am
vscid wrote:If 6xy = x^2y + 9y, what is the value of xy?

(1) x = -2

(2) x < 0
lets solve the equation first

6xy-y.x^2-9y = 0
y(6x-x^2-9) = 0
y = 0 or (x-3)^2 = 0
y = 0 or x = +3

st1) x = -2 ie x not equal to +3 so y definitely equal to 0, hence product xy = 0
st2) x < 0, it means x cannot be 3, so y definitely equals to 0, hence product
xy = 0

Hence it can be answered from both st1 and st2 independently
Top
Senior | Next Rank: 100 Posts
Posts: 43
Joined: Sat Mar 13, 2010 4:11 am
Thanked: 1 times

by STEVEN SPIELBERG » Mon Mar 15, 2010 11:11 am
IMOD.
I want to win an OSCAR on the GMAT !!!
Top
Post new topic Post Reply
• Page 1 of 1