Find the middle terms in the expansions of `(3-x^3/6)^7`.

Explanation

In the expansion of `(3-(x^(3))/(6))^(7)`
No. of terms `=7+1=8`(even)
So. Here will be two middle terms .
Middle terms`=(8)/(2)`th term and `((8)/(2)+1)`th term
=4th term and 5th term
`T_(4)=T_(3+1)`
`=^(7)C_(3)(3)^(7-3).(-(x^(3))/(6))^(3)`
`=35 xx 81 xx ((-x^(9)))/(216)=(-105)/(8).x^(9)`
`" and " T_(5)=T_(4+1)`
`=^(7)C_(4)(3)^(7-4).((-x^(3))/(6))^(4)`
`=(35xx27xx x^(12))/(1296) =(35x^(12))/(48)`