Let
$A=\left[\begin{array}{ll}2 & -5 \\ 1 & -3\end{array}\right] \quad B=\left[\begin{array}{ll}4 & 3 \\ 1 & 1\end{array}\right] \quad C=\left[\begin{array}{rr}2 & 3 \\ -2 & 1\end{array}\right]$
a. Find $A B C, A^{-1}, B^{-1}$, and $C^{-1}$.
b. Show that $(A B C)^{-1}=C^{-1} B^{-1} A^{-1}$.