Answer
$2304$
Work Step by Step
Since we have $$\left[\begin{array}{rrr} {4} & {16}&{0} \\ {12} & {-8}&{8}\\{16}&{20}&{-4}\end{array}\right]=4\left[\begin{array}{rrr} {1} & {4}&{0} \\ {3} & {-2}&{2}\\{4}&{5}&{-1}\end{array}\right]=4\left[\begin{array}{rrr} {1} & {4}&{0} \\ {11} & {8}&{0}\\{4}&{5}&{-1}\end{array}\right]$$
then, we get
$$\left|\begin{array}{rrr} {4} & {16}&{0} \\ {12} & {-8}&{8}\\{16}&{20}&{-4}\end{array}\right|=4^3\left|\begin{array}{rrr} {1} & {4}&{0} \\ {11} & {8}&{0}\\{4}&{5}&{-1}\end{array}\right|=64(-1)(8-44)=2304.$$
