Matrices & Systems · Medium problem

Invertible matrices $A$ and $B$ have $A^{-1} = \begin{pmatrix}2 & 1\\0 & 3\end{pmatrix}$ and $B^{-1} = \begin{pmatrix}1 & -1\\2 & 4\end{pmatrix}$. Find the entry in row 1, column 2 of $(AB)^{-1}$.