We use cookies to personalise content and advertisements and to analyse access to our website. Furthermore, our partners for online advertising receive pseudonymised information about your use of our website. cookie policy and privacy policy.
 
+0  
 
0
231
2
avatar

  Need some help with this please.

 

 

 Oct 24, 2018
 #1
avatar+28135 
+1

The question is: "What is the coefficient of a4b4 in the expansion of (a2/3 + 2b)6?"

 

In general: (x + y)6 = x6+6*x5*y+15*x4*y2+20*x3*y3+15*x2*y4+6*x*y5+y6

 

In your case x = a2/3 and y = 2b

 

I'm sure you can take it from here.

 Oct 24, 2018
edited by Alan  Oct 24, 2018
 #2
avatar
0

[6C2] X [a^2/3(First term of original binomial)]^(desired power(2)) X [2b(Second term of original binomial)]^(desired power(4)) 
(6C2 ) x (a^2/3)^2 x (2b)^4= 15 x a^4/9 x 16b^4=(15 x 16)/9a^4b^4=80/3a^4b^4

 Oct 24, 2018
edited by Guest  Oct 24, 2018

27 Online Users