Answer
$n$
Work Step by Step
$\binom{n}{n-1} =\dfrac {n!}{\left( n-1\right) !\left( n-\left( n-1\right) \right) !}=\dfrac {n!}{\left( n-1\right) !\times 1!}=\dfrac {n!}{\left( n-1\right) !}=n$
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