Another Vic

This topic has expert replies
User avatar
Senior | Next Rank: 100 Posts
Posts: 58
Joined: Thu Jul 22, 2010 5:40 pm
Thanked: 1 times

Another Vic

by Jinglander » Thu Aug 12, 2010 3:38 pm
If ab=x and a/b=y and ab does not equal 0 then what is a^2-b^2. How do you get the answer

It is x(y-1)(y+1)/y

GMAT/MBA Expert

User avatar
GMAT Instructor
Posts: 1179
Joined: Sun Apr 11, 2010 9:07 pm
Location: Milpitas, CA
Thanked: 447 times
Followed by:88 members

by Rahul@gurome » Thu Aug 12, 2010 4:09 pm
Jinglander wrote:If ab=x and a/b=y and ab does not equal 0 then what is a^2-b^2. How do you get the answer

It is x(y-1)(y+1)/y
Multiplying ab=x and a/b=y we get, a^2 = xy
ab=x implies a^2.b^2 = x^2 or b^2 = x^2/a^2 = x^2/xy = x/y
So, a^2-b^2 = xy - x/y = (x.y^2 - x)/y = x(y^2 -1)/y = x(y-1)(y+1)/y
Rahul Lakhani
Quant Expert
Gurome, Inc.
https://www.GuroMe.com
On MBA sabbatical (at ISB) for 2011-12 - will stay active as time permits
1-800-566-4043 (USA)
+91-99201 32411 (India)