\begin{bmatrix}
\dfrac{\partial x_{1}}{\partial y_{1}} & \dfrac{\partial x_{2}}{\partial y_{1}} \\
\  \\
\dfrac{\partial x_{1}}{\partial y_{2}} & \dfrac{\partial x_{2}}{\partial y_{2}} \\
\end{bmatrix}\begin{pmatrix}
1 & 2 \\
3 & 4 \\
\end{pmatrix}\begin{Bmatrix}
1 & 2 \\
3 & 4 \\
\end{Bmatrix}\begin{vmatrix}
1 & 2 \\
3 & 4 \\
\end{vmatrix}\begin{Vmatrix}
1 & 2 \\
3 & 4 \\
\end{Vmatrix}
