Find the coefficient of `x^5` in `(x+3)^8`

Explanation

To find the coefficient of \( x^5 \) in the expansion of \( (x + 3)^8 \), we can use the Binomial Theorem, which states that:

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

In our case, \( a = x \), \( b = 3 \), and \( n = 8 \). We want to find the term that contains \( x^5 \).

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