For ,

a= x⁴, and n=11

As n is odd, there are two middle terms i.e.

II. and II.

General term t_r+1 is given by,

I. The first middle term is

Therefore, for the 6^th middle term, r=5

Therefore, the first middle term is

= - 462. x⁹

II. The second middle term is

Therefore, for the 7^th middle term, r=6

Therefore, the second middle term is

………

= 462. x²