Answer
The required solution is
$\left( \begin{align}
& 8 \\
& 2 \\
\end{align} \right)=\underline{\frac{8!}{2!6!}}$
Work Step by Step
We know that for non-negative integers n and r, with $n\ge r$, the expression $\left( \begin{align}
& n \\
& r \\
\end{align} \right)$ (read as “n above r”) is called the binomial coefficient and is defined by
$\left( \begin{align}
& n \\
& r \\
\end{align} \right)=\frac{n!}{r!\left( n-r \right)!}$ … (1)
Since, $n=8\text{ and }r=2$, substituting in (1), we obtain,
$\left( \begin{align}
& 8 \\
& 2 \\
\end{align} \right)=\frac{8!}{2!\left( 8-2 \right)!}$
$\left( \begin{align}
& 8 \\
& 2 \\
\end{align} \right)=\frac{8!}{2!6!}$
