My Math Forum  

Go Back   My Math Forum > College Math Forum > Calculus

Calculus Calculus Math Forum

Thanks Tree1Thanks
  • 1 Post By v8archie
LinkBack Thread Tools Display Modes
May 15th, 2014, 06:00 PM   #1
Joined: May 2014
From: Leeds

Posts: 3
Thanks: 0

Bracket expansion problem

I hope this is in the right forum... How do I expand this?

I know easy expansions like (3-2y)^2 but I don't know how to do this.
Any help always appreciated.

pcurran871 is offline  
May 15th, 2014, 06:22 PM   #2
Math Team
Joined: Dec 2013
From: Colombia

Posts: 7,618
Thanks: 2608

Math Focus: Mainly analysis and algebra
$$2(3-x-2y)^2 = 2(3-x-2y)(3-x-2y)$$
And now each term in the first bracket multiplies each term in the second bracket (just as if there were only two terms in each bracket).
2(3-x-2y)^2 &= 2\left(\underbrace{(9 - 3x -6y)}_{3(3 - x -2y)} + \underbrace{(-3x + x^2 + 2xy)}_{-x(3 - x - 2y)} + \underbrace{(-6y + 2xy + 4y^2)}_{-2y(3-x-2y)}\right) \\
&= 2(9 - 6x -12y +x^2 +4xy +4y^2) \\
&= 18 - 12x -24y +2x^2 +8xy +8y^2 \\
Thanks from pcurran871
v8archie is offline  

  My Math Forum > College Math Forum > Calculus

bracket, expansion, problem

Thread Tools
Display Modes

Similar Threads
Thread Thread Starter Forum Replies Last Post
fraction and bracket equation Rob158 Algebra 7 April 17th, 2014 11:03 AM
expansion MATHEMATICIAN Number Theory 5 September 4th, 2013 06:53 AM
Fourier expansion Problem clumsy shark Real Analysis 4 May 23rd, 2013 08:49 PM
expansion apoorva Algebra 4 April 26th, 2013 10:20 PM
Expansion Sarge99 Algebra 4 October 15th, 2009 05:51 PM

Copyright © 2019 My Math Forum. All rights reserved.