Chapter 5 Polynomials and Polynomial Functions - 5.7 Apply the Fundamental Theorem of Algebra - 5.7 Exercises - Mixed Review - Page 386: 68

$-24$

$det=\begin{vmatrix} 15 & 4 & -9 \\ 10 & 0 & 2 \\-8 &2 & -7 \end{vmatrix} \begin{matrix} 15 & 4 \\ 10 & 0 \\-8 &2 \end{matrix}$ $=[(15)(0)(-7)]+[(4)(2)(-8)+[(-9)(10)(2)]-[(-8)(0)(-9)+(2)(2)(15)+(-7)(10)(4)]]$ $det=0-64-180-(0+60-280)$ $det=-244-(-220)=-24$