Find the middle term in the expansion of `(3x-(x^3)/6)^9`

Explanation

To find the middle term in the expansion of \( (3x - \frac{x^3}{6})^9 \), we follow these steps:

### Step 1: Determine the number of terms in the expansion
The number of terms in the expansion of \( (a + b)^n \) is given by \( n + 1 \). Here, \( n = 9 \), so the number of terms is:
\[ 9 + 1 = 10 \]

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