Answer:
So, the coefficient of x8 in the given expansion will be 210.
Step-by-step explanation:
We know,
General term in (x+a)n is given by,
Tr+1=C(n,r)xn−rar
∴ General term in (x2−1x)10 ,
Tr+1=C(10,r)(x2)10−r(−1x)r
⇒Tr+1=(−1)rC(10,r)x20−2rx−r
Now, we have to find the term having coefficient x8.
∴20−2r−r=8⇒r=4
So, T5 will have coefficient x8.
∴T5=(−1)4C(10,4)x8
⇒T5=10⋅9⋅8⋅74⋅3⋅2⋅1x8
⇒T5=210x8
