Calculus 8th Edition

$9$
Volume of a parallelepiped is defined as: $V=|a \cdot (b \times c)|$ $b \times c= \lt -1,1,2 \gt \times \lt 2,1,4 \gt=\lt 2,8,-3 \gt$ $a \cdot (b \times c)= \lt 1,2,3 \gt \cdot \lt 2,8,-3 \gt$ $=1 \cdot2+2 \cdot 8+ 3 \cdot (-3)$ $=2+16+(-9)$ $=9$