Question

evaluate the given expression.
p(n, 1)
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1. - / 1 points

evaluate the given expression.
p(k, 2)
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Explanation:

Step1: Recall permutation formula

The permutation formula is $P(n,k)=\frac{n!}{(n-k)!}$

Step2: Substitute k=2 into formula

$P(k,2)=\frac{k!}{(k-2)!}$

Step3: Expand factorial to simplify

$\frac{k!}{(k-2)!}=\frac{k\times(k-1)\times(k-2)!}{(k-2)!}=k(k-1)$

Step4: Expand the product

$k(k-1)=k^2 - k$

Answer:

$k^2 - k$ (or $k(k-1)$)