n choose k

\({n \choose k} = _{n}^{k}\textrm{C}= \frac{n!}{k!(n-k)!}\)

https://byjus.com/n-choose-k-formula/

\((x+y)^n = \sum_{k=0}^n %{n \choose k} x^{n - k} y^k\)

\begin{equation} \label{eq:1} C = W\log_{2} (1+\mathrm{SNR}) \end{equation}

binomial theorem

In elementary algebra, the binomial theorem describes the algebraic expansion of powers of a binomial.

\((a+b)^n=\sum_{k=0}^n{n\choose k}a^{n-k}b^k\)