Question

Which statement about the binomial expansion of (x2 – x)9 is true?

Answer 1

Answer:

Option D.

Step-by-step explanation:

The given expression is

$(x^2-x)^9$

Here, n=9, p=x^2 adn q=-x.

kth term in the binomial expansion of $(p+q)^n$ is

$T_{r}=^nC_{r-1}p^{n-r+1}q^{r-1}$

First term of the binomial expansion of $(x^2-x)^9$ is

$T_{1}=^9C_{1-1}(x^2)^{9-1+1}(-x)^{1-1}=x^{18}$

Second term of the binomial expansion of $(x^2-x)^9$ is

$T_{2}=^9C_{2-1}(x^2)^{9-2+1}(-x)^{2-1}=9(x^16)(-x)=-9x^{17}$

Third term of the binomial expansion of $(x^2-x)^9$ is

$T_{3}=^9C_{3-1}(x^2)^{9-3+1}(-x)^{3-1}=9(x^14)(x^2)=36x^{16}$

Last or 10th term of the binomial expansion of $(x^2-x)^9$ is

$T_{10}=^9C_{10-1}(x^2)^{9-10+1}(-x)^{10-1}=1(x^0)(-x^9)=-x^{9}$

Therefore, the correct option is D.

Answer 2

Answer:

D

Step-by-step explanation:

just took it