SOLUTION: obtain the term involving x^3 in expansion of (2x-1/2)^7

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Question 970463: obtain the term involving x^3 in expansion of (2x-1/2)^7
Answer by Boreal(15235) About Me  (Show Source):
You can put this solution on YOUR website!
binomial expansion
1
1 2 1
1 3 3 1
1;; 4;; 6 ;; 4; 1
1; 5; 10;; 10 ;;5;; 1
1 ;;6;; 15;; 20;; 15;; 6 ;;1
1 ;;7 ;;21;; 35;; 35;; 21;; 7;; 1
(2x) is the leading term
The first term is (2x)^7
The second term is 7 (2x)^6
The x^3 term is the fifth number in the sequence
it is 35 (2x)^3
Remember that the 2 has to be cubed as well
So the term involving x^3 is 280 x^3