penyelesainnya apa ya?

(AB-2C)
A = [tex] \left[\begin{array}{ccc}-3\\20\end{array}\right] [/tex]
B = [tex] \left[\begin{array}{ccc}8\\-3\end{array}\right] [/tex]
C = [tex] \left[\begin{array}{ccc}0\\5\end{array}\right] [/tex]
(AB-2C) = (([tex] \left[\begin{array}{ccc}-3\\20\end{array}\right] [/tex])([tex] \left[\begin{array}{ccc}8\\-3\end{array}\right] [/tex])-2([tex] \left[\begin{array}{ccc}0\\5\end{array}\right] [/tex])
hasilnya = ([tex] \left[\begin{array}{ccc}-24\\-60\end{array}\right] [/tex] - [tex] \left[\begin{array}{ccc}0\\10\end{array}\right] [/tex]
dan hasil akhirnya = [tex] \left[\begin{array}{ccc}-24\\-70\end{array}\right] [/tex]
maaf kalo salah