Hello everyone!

I have some questions about equatuons:

1) I want to get from rst source latex code like this: How can I do this? Would it be ok just to use two math:: directives each with :label: option? The question is on alignment.

I have some questions about equatuons:

1) I want to get from rst source latex code like this: How can I do this? Would it be ok just to use two math:: directives each with :label: option? The question is on alignment.

\begin{eqnarray}

m_1\ddot{x}_1+(k_1+k_2)x_1-k_2x_2 & = & u_1, \label{spmass1}\\

m_2\ddot{x}_2-k_2x_1+(k_1+k_2)x_2 & = & u_2 . \label{spmass2}

\end{eqnarray}

2) Is it possible to get labels for equations like these:

\begin{equation}`\dot{x}(t) = f(t, x, u),`

\label{ctds1}\end{equation}\begin{equation}`x(t+1) = f(t, x, u),`

`\tag*{(\ref{ctds1}d)}`

\label{dtds1}\end{equation} ?`I mean I want labels to look like (1) and (1d), for example.`

`3) What about referencing equation from another file (chapter)? Is it possible?`

Lukashevichus Ksenia.