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What is the coefficient for the third term in the expansion?

What is the coefficient for the third term in the expansion?-example-1

2 Answers

2 votes

Answer:

2196

Explanation:

3^2 = 9

9+3^7 = 2196

User Austin Mullins
by
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3 votes

ANSWER

21

EXPLANATION

The given by binomial expression is:


( {x}^(2) + y)^(7)

Comparing this to


(a+ b)^(n)

We have:


n = 7


a = {x}^(2)


b = y

The coefficient of the (r+1)th term is given by:


\binom{n}{r}

We want to find the coefficient of the third term:


r + 1 = 3


r = 2

Therefore the coefficient is:


\binom{7}{2} = 21

The coefficient of the third term is 21.