## Precalculus (6th Edition) Blitzer

Published by Pearson

# Chapter 8 - Section 8.5 - Determinants and Cramer's Rule - Exercise Set - Page 945: 28

#### Answer

$-20$.

#### Work Step by Step

Expand with ${{R}_{1}}$ \begin{align} & \left| \begin{matrix} 1 & 2 & 3 \\ 2 & 2 & -3 \\ 3 & 2 & 1 \\ \end{matrix} \right|=1\left( 2-\left( -6 \right) \right)-2\left( 2-\left( -9 \right) \right)+3\left( 4-6 \right) \\ & =8-22-6 \\ & =-20 \end{align}

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