SOLUTION: Find the third term in the expansion of (w+2x)^8. (A) none of these (B) 112w^6x^2 (C) 299w^5x^3 (D) 56w^4x^4 Thank you

Algebra ->  College  -> Linear Algebra -> SOLUTION: Find the third term in the expansion of (w+2x)^8. (A) none of these (B) 112w^6x^2 (C) 299w^5x^3 (D) 56w^4x^4 Thank you      Log On


   

Question 31749: Find the third term in the expansion of (w+2x)^8.
(A) none of these
(B) 112w^6x^2
(C) 299w^5x^3
(D) 56w^4x^4
Thank you
Answer by venugopalramana(3286) About Me  (Show Source):
You can put this solution on YOUR website!
(W+2X)^8
AS PER BINOMIAL THEOREM IN EXPANSION OF (X+A)^N..THE GENERAL TERM IS GIVEN BY
T(R+1)=NCR*(X^(N-R))*(A^R)
HERE WE HAVE W AS X AND 2X AS A AND N=8....SO...
T(R+1)=NCR*W^(N-R)*(2X)^R.....WE WANT T3....R+1=3......R=2......
T3=8C2*W^(8-2)*(2X)^2=(8*7/2)*W^6*4X^2=112W^6*X^2
B IS THE ANSWER