Find 13th term in the expansion of `(9x-1/(3sqrtx))^(18),\ x!=0.`

Explanation

To find: `13^{ {th }}` term in the expansion of `(9 x-frac{1}{3 sqrt{x}})^{18}`

Formula used: (i)

`\ ^{{n}} {C}_{{r}}=frac{n !}{(n-r) !(r) !}`

(ii) `T_{r+1}=\ ^{n} C_{r} a^{n-r} b^{r}`

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