The answer is 0. Note that ${\left[\begin{array}{cc}1& 2\\ 4& 3\end{array}\right]}^{\mathsf{T}}+\left[\begin{array}{cc}-1& 0\\ 2& -2\end{array}\right]=\left[\begin{array}{cc}1& 4\\ 2& 3\end{array}\right]+\left[\begin{array}{cc}-1& 0\\ 2& -2\end{array}\right]=\left[\begin{array}{cc}0& 4\\ 4& 1\end{array}\right]$.