# equation and sub equation not properly formatted

I want to write down this equation in latex.

\bar\Omega_t=\bar\Sigma_t^{-1}
=[G_t\Sigma_{t-1}G_t^T+F_x^TR_t^xF_x]


The code I write down in latex to display this equation is

$$\bar\Omega_t=\bar\Sigma_t^{-1} =[G_t\Sigma_{t-1}G_t^T+F_x^TR_t^xF_x]$$


It throws error. Also I want a line by line output meaning \bar\Omega_t=\bar\Sigma_t^{-1} equation line no: 1 and =[G_t\Sigma_{t-1}G_t^T+F_x^TR_t^xF_x] equation lin no: 2. How could I do that?

I thing useing align from amsmath package would be better.

\documentclass{article}
\usepackage{amsmath}
\begin{document}
\begin{align}
\bar\Omega_t&=\bar\Sigma_t^{-1}\\
&=[G_t\Sigma_{t-1}G_t^T+F_x^TR_t^xF_x]
\end{align}
\end{document}


it is not clear what is your problem. see if any of following example is what you like to obtain:

\documentclass{article}
\usepackage{amsmath}

\begin{document}
$$\bar\Omega_t = \bar\Sigma_t^{-1} = [G_t\Sigma_{t-1}G_t^T+F_x^TR_t^xF_x]$$

$$\begin{split} \bar\Omega_t & = \bar\Sigma_t^{-1} \\ & = [G_t\Sigma_{t-1}G_t^T+F_x^TR_t^xF_x] \end{split}$$

\begin{align}
\bar\Omega_t & = \bar\Sigma_t^{-1} \\
& = [G_t\Sigma_{t-1}G_t^T+F_x^TR_t^xF_x]
\end{align}
\end{document}