## Algebra and Trigonometry 10th Edition

Published by Cengage Learning

# Chapter 11 - 11.6 - Counting Principles - 11.6 Exercises - Page 825: 89

#### Answer

The identity is verified. $_nC_{n-1}=~_nC_1$

#### Work Step by Step

$_nC_{n-1}=\frac{n!}{[n-(n-1)]!(n-1)!}=\frac{n!}{1!~(n-1)!}=\frac{n!}{(n-1)!~1!}=~_nC_1$ It can also be verified that: $_nC_{n-1}=~_nC_1=n$

After you claim an answer you’ll have 24 hours to send in a draft. An editor will review the submission and either publish your submission or provide feedback.