Chapter A.3, Problem 11P

Let $\text{A}=\left(\begin{array}{ccc}1& 3& 0\\ -1& 2& 4\\ 1& -2& 0\end{array}\right)$ and $\text{B}=\left(\begin{array}{ccc}2& 0& 1\\ -1& 3& 2\\ 4& 0& 0\end{array}\right)$

Verify that $\left|\text{AB}\right|\text{=}\left|\text{A}\right|\left|\text{B}\right|$.