Calcular determinantes

Calcula los determinantes de las siguientes matrices
 A =
\left(
\begin{array}{cc}
     1 & -8
  \\ 0 & 3 
\end{array}
\right)
\qquad B=
\left(
\begin{array}{cc}
     3 & -1 
  \\ -15 & -4
\end{array}
\right)

C =
\left(
\begin{array}{ccc}
     1 & -2 & 1
  \\ 0 & -2 & 4
  \\ 1 & 3 & 5
\end{array}
\right)
\qquad  D =
\left(
\begin{array}{ccc}
     5 & -1 & 2
  \\ 1 & 2 & 3
  \\ 6 & 1 & 5
\end{array}
\right)