\documentclass[12pt]{article}
\begin{document}
\begin{eqnarray}
\begin{array}{cc}
  M_1^1(V)= \frac{\varepsilon^{-1}(V)(-i(c\tau + d))^{-k}}{b_{11}} & M_2^1=-\frac{b_{12}}{b_{11}} \\
  M_1^2=-\frac{b_{21}}{b_{22}} & \frac{\varepsilon^{-1}(V)(-i(c\tau + d))^{-k}}{b_{22}} \\
\end{array}
\end{eqnarray}
\end{document}