Use equation and cases for big and numerous equation

Question

I have a system of differential equations I want to write. Some equations are very long and there are numerous.

I wonder if there is a way to split the equations (automaticaly if possible) and to split the system. And any advide on how handle big systems is welcomed. (write the system is a good/bad idea, a table is better... anything you want)

Here is a prototype of my code

\documentclass[a4paper]{article}
\usepackage{amssymb}
\usepackage{amsmath}

\begin{document}
    \begin{equation}
        \begin{cases}
            \frac{dx}{dt} = \nu\alpha\beta\gamma + \nu\alpha\beta\gamma + \nu\alpha\beta\gamma + \nu\alpha\beta\gamma + \nu\alpha\beta\gamma + \nu\alpha\beta\gamma + \nu\alpha\beta\gamma + \nu\alpha\beta\gamma + \nu\alpha\beta\gamma + \nu\alpha\beta\gamma + \nu\alpha\beta\gamma + \nu\alpha\beta\gamma + \nu\alpha\beta\gamma + \nu\alpha\beta\gamma + \nu\alpha\beta\gamma + \nu\alpha\beta\gamma + \nu\alpha\beta\gamma + \nu\alpha\beta\gamma + \nu\alpha\beta\gamma + \nu\alpha\beta\gamma\\
            \frac{dx}{dt} = \nu\alpha\beta\gamma \\
            \frac{dx}{dt} = \nu\alpha\beta\gamma \\
            \frac{dx}{dt} = \nu\alpha\beta\gamma \\
            \frac{dx}{dt} = \nu\alpha\beta\gamma \\
            \frac{dx}{dt} = \nu\alpha\beta\gamma \\
            \frac{dx}{dt} = \nu\alpha\beta\gamma \\
            \frac{dx}{dt} = \nu\alpha\beta\gamma \\
            \frac{dx}{dt} = \nu\alpha\beta\gamma \\
            \frac{dx}{dt} = \nu\alpha\beta\gamma \\
            \frac{dx}{dt} = \nu\alpha\beta\gamma \\
            \frac{dx}{dt} = \nu\alpha\beta\gamma \\
            \frac{dx}{dt} = \nu\alpha\beta\gamma \\
            \frac{dx}{dt} = \nu\alpha\beta\gamma \\
            \frac{dx}{dt} = \nu\alpha\beta\gamma \\
            \frac{dx}{dt} = \nu\alpha\beta\gamma \\
            \frac{dx}{dt} = \nu\alpha\beta\gamma \\
            \frac{dx}{dt} = \nu\alpha\beta\gamma \\
            \frac{dx}{dt} = \nu\alpha\beta\gamma \\
            \frac{dx}{dt} = \nu\alpha\beta\gamma \\
            \frac{dx}{dt} = \nu\alpha\beta\gamma \\
            \frac{dx}{dt} = \nu\alpha\beta\gamma \\
            \frac{dx}{dt} = \nu\alpha\beta\gamma \\
            \frac{dx}{dt} = \nu\alpha\beta\gamma \\
            \frac{dx}{dt} = \nu\alpha\beta\gamma \\
            \frac{dx}{dt} = \nu\alpha\beta\gamma \\
            \frac{dx}{dt} = \nu\alpha\beta\gamma \\
            \frac{dx}{dt} = \nu\alpha\beta\gamma \\
            \frac{dx}{dt} = \nu\alpha\beta\gamma \\
            \frac{dx}{dt} = \nu\alpha\beta\gamma \\
            \frac{dx}{dt} = \nu\alpha\beta\gamma \\
            \frac{dx}{dt} = \nu\alpha\beta\gamma \\
            \frac{dx}{dt} = \nu\alpha\beta\gamma \\
            \frac{dx}{dt} = \nu\alpha\beta\gamma \\
            \frac{dx}{dt} = \nu\alpha\beta\gamma \\
            \frac{dx}{dt} = \nu\alpha\beta\gamma \\
            \frac{dx}{dt} = \nu\alpha\beta\gamma \\
            \frac{dx}{dt} = \nu\alpha\beta\gamma \\
            \frac{dx}{dt} = \nu\alpha\beta\gamma \\
            \frac{dx}{dt} = \nu\alpha\beta\gamma \\
            \frac{dx}{dt} = \nu\alpha\beta\gamma \\
            \frac{dx}{dt} = \nu\alpha\beta\gamma \\
            \frac{dx}{dt} = \nu\alpha\beta\gamma \\
            \frac{dx}{dt} = \nu\alpha\beta\gamma \\
            \frac{dx}{dt} = \nu\alpha\beta\gamma \\
            \frac{dx}{dt} = \nu\alpha\beta\gamma \\
            \frac{dx}{dt} = \nu\alpha\beta\gamma \\
            \frac{dx}{dt} = \nu\alpha\beta\gamma \\
            \frac{dx}{dt} = \nu\alpha\beta\gamma \\
            \frac{dx}{dt} = \nu\alpha\beta\gamma \\
            \frac{dx}{dt} = \nu\alpha\beta\gamma \\
            \frac{dx}{dt} = \nu\alpha\beta\gamma \\
            \frac{dx}{dt} = \nu\alpha\beta\gamma \\
            \frac{dx}{dt} = \nu\alpha\beta\gamma \\
            \frac{dx}{dt} = \nu\alpha\beta\gamma \\
            \frac{dx}{dt} = \nu\alpha\beta\gamma \\
            \frac{dx}{dt} = \nu\alpha\beta\gamma \\
        \end{cases}
    \end{equation}
\end{document}

Answer 1

Some suggestions/observations:

• Since the system of differential equations looks like it might span more than 1 page, you should not use an equation environment. Instead, use either an align or align* (the latter if you do not need equation numbers) environment, along with an \allowdisplaybreaks statement.

• It seems pointless to use a cases environment if the equations end up spanning 2 or more pages. However, I may be missing something.

• If you have a long expression on the right-hand side, encase it in a \parbox directive, as is shown below. That way, you'll get automatic line-breaking, which would appear to be one of your objectives.

\documentclass{article}
\usepackage{amssymb,amsmath}
\allowdisplaybreaks
\begin{document}

\begin{align*}
     \frac{dx}{dt} &= \parbox[t]{0.75\textwidth}{\raggedright%
     $\nu\alpha\beta\gamma + \nu\alpha\beta\gamma + \nu\alpha\beta\gamma + \nu\alpha\beta\gamma + \nu\alpha\beta\gamma + \nu\alpha\beta\gamma + \nu\alpha\beta\gamma + \nu\alpha\beta\gamma + \nu\alpha\beta\gamma + \nu\alpha\beta\gamma + \nu\alpha\beta\gamma + \nu\alpha\beta\gamma + \nu\alpha\beta\gamma + \nu\alpha\beta\gamma + \nu\alpha\beta\gamma + \nu\alpha\beta\gamma + \nu\alpha\beta\gamma + \nu\alpha\beta\gamma + \nu\alpha\beta\gamma + \nu\alpha\beta\gamma$}\\
     \frac{dx}{dt} &= \nu\alpha\beta\gamma \\
     \frac{dx}{dt} &= \nu\alpha\beta\gamma \\
     \frac{dx}{dt} &= \nu\alpha\beta\gamma
\end{align*}

\end{document}