Determine the constant term in the expansion of (x+2)^9

3 Answers

thilina-g's profile pic

thilina-g | College Teacher | (Level 1) Educator

Posted on

The constant term of a binomial expansion of nth order `(x+a)^n` is iven by `a^n` .

Therefore the constant term  `= 2^9`

                                          `= 512`


Therefore the constant term of `(x+2)^9` is 512.

rcmath's profile pic

rcmath | High School Teacher | (Level 1) Associate Educator

Posted on

The binomial expansion states `(a+b)^n=sum_(k=0)^n(nCk)a^(n-k)b^k`

In our case `(x+2)^9=sum_(k=0)^9(9Ck)x^(9-k)2^k`

The only term without x will be when k=9 => x^0=1. Hence that term will be equal to `9C9*1*2^9=1*1*512=512`

So the only constant is 512

baronridiculous's profile pic

baronridiculous | College Teacher | (Level 1) eNoter

Posted on

The expansion would look like:

x^9 + ....... + 2^9

We only care about the last term:

2^9 = 512