Forgot Password?
 
Links
About Arcadia LSAT Shorthand NotationArcadia Prep's GMAT CourseArcadia Prep's LSAT CourseArcadia Prep's SAT CourseArcadia Prep's GRE CourseThe Simply Brilliant GMAT AppAbout the MCATMCAT Physical and Biological SciencesAbout Arcadia Prep's MCAT CourseTerms of SaleTerms of UseAbout Arcadia Apps
iPhone App Store
GGRE Prep App
GMAT Prep App
LSAT Prep App
LSAT Prep
SAT Prep App
 
Back to Questions

If x + y = k, then 3x2 + 6xy + 3y2 =

If x + y = k, then 3x2 + 6xy + 3y2 =


(A)

   k


(B) ...
(C) ...
(D) ...
(E) ...

*This question is included in Nova Math - Diagnostic/Review:

Collapse All Subordinate Threads
Image Not Available
 
Replies to This Thread: 0 | ----
 
Posted: 03/08/2012 19:30
I do not understand where the (x+y)^2 came from ?
Contributor
 
Replies to This Thread: 0 | ----
 
Posted: 03/09/2012 01:33
Crystal, it comes from first factoring out 3, which gives us 3(x^2 + 2xy + y^2). We recognize that the resulting term in the bracket is a square of (x+y)^2. This is something you should remember from algebra. Since x+y = k, ...
Image Not Available
 
Replies to This Thread: 0 | ----
 
Posted: 02/03/2013 11:20
What happened to the 2xy in the equation?
Image Not Available
 
Replies to This Thread: 0 | ----
 
Posted: 02/03/2013 11:21
Never mind. I figured it out. Thanks!
Image Not Available
 
Replies to This Thread: 1 | ----
 
Posted: 04/07/2013 15:24
I understand everything up to the point of factoring out 3.. Im puzzled about what to do next?
Arcadia
Admin
Reply 1 of 1
Replies to This Thread: 0 | ----
 
Posted: 04/07/2013 17:48
Hi Ivana,

Using the Perfect Square Trinomial formula, we rewrote

x^2 + 2xy + y^2

as

(x + y)^2

So 3(x^2 + 2xy + y^2) became 3(x + y)^2.

Since we are given that x + y = k, 3(x + y)^2 became 3k^2.

Nova Press
Arcadia Prep © 2012.
Contact Arcadia  |  Terms of Use  |  Terms of Sale  |  Change Log-in Info