Find the middle term (terms) in the expansion of
(i) `((x)/(a) - (a)/(x))^(10)` (ii) `(3x - (x^(3))/(6))^(9)`

Explanation

To find the middle term(s) in the given expansions, we will use the Binomial Theorem. The Binomial Theorem states that:

\[ (x + y)^n = \sum_{r=0}^{n} \binom{n}{r} x^{n-r} y^r \]

Where \(\binom{n}{r}\) is the binomial coefficient.

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