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Ch. 8 - Sequences, Induction, and Probability
Blitzer - College Algebra 8th Edition
Blitzer8th EditionCollege AlgebraISBN: 9780136970514Non è quello che usi tu?Cambia libro di testo
Capitolo 9, Problema 1

Use the formula for nPr to evaluate each expression. 9P4

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1
Recall the formula for permutations: \(nP_r = \frac{n!}{(n-r)!}\), where \(n\) is the total number of items and \(r\) is the number of items to arrange.
Identify the values of \(n\) and \(r\) from the problem: here, \(n = 9\) and \(r = 4\).
Substitute these values into the formula: \(9P4 = \frac{9!}{(9-4)!} = \frac{9!}{5!}\).
Write out the factorial expressions to simplify: \(9! = 9 \times 8 \times 7 \times 6 \times 5!\), so \(\frac{9!}{5!} = \frac{9 \times 8 \times 7 \times 6 \times 5!}{5!}\).
Cancel the common \$5!$ terms to get \(9P4 = 9 \times 8 \times 7 \times 6\), which you can then multiply to find the final value.

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Permutation (nPr)

A permutation refers to the arrangement of objects in a specific order. The notation nPr represents the number of ways to arrange r objects out of n distinct objects, where order matters.
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Introduction to Permutations

Permutation Formula

The formula for permutations is nPr = n! / (n - r)!, where n! denotes the factorial of n. This formula calculates the total number of ordered arrangements of r items selected from n.
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Factorial Function

The factorial of a positive integer n, written as n!, is the product of all positive integers from 1 to n. It is essential in permutation calculations to determine the number of possible arrangements.
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