How can I \label \subsection in \intertext inside flalign? (LATEX) - latex

Question

I have one flalign environment, so columns are aligned same way whole page. I need \subsections inside this flalign, so I used \intertext. And I need \label these \subsections. And thats where I failed. It \label first equation after \subsection but not \subsection itself or error occurs.
Image:
When I tried to use more flalign environments and place subsections between them they were not aligned same way and it looked terible.
Thanks for help.
\begin{flalign}
&\text{Značení: } &&X\sim \text{Exp($\lambda$)} &&
\\
&\text{Parametry: } &&\lambda > 0 &&
\\
&\text{Nosič: } &&X \in (0,\infty) &&
\\
&\text{Hustota: } &&f(x)=
\begin{cases}
\lambda e^{-\lambda x} & x>0
\\
0 & x\leq 0
\end{cases}
\\
&\text{Distribuční funkce: } &&F(x)=
\begin{cases}
1-e^{-\lambda x} & x>0
\\
0 & x\leq 0
\end{cases} &&
\\
&\text{Střední hodnota: } && \E X = \frac{1}{\lambda} &&
\\
&\text{Rozptyl: } && \var X = \frac{1}{\lambda^2} &&
\\
\intertext{\subsection{Weibullovo rozdělení}}\label{priloha:weibdist}
&\text{Značení: } &&X\sim \text{Weib($\alpha$, $\beta$)}&&
\\
&\text{Parametry: } &&\text{$\alpha$, $\beta>0$}&&
\\
&\text{Nosič: } &&X \in \langle 0,\infty)&&
\\
&\text{Hustota: } &&f(x)=
\begin{cases}
\alpha \beta^\alpha x^{\alpha-1} e^{-(\beta x)^\alpha} & x\geq 0
\\
0 & x< 0
\end{cases}&&
\\
&\text{Distribuční funkce: } &&F(x)=
\begin{cases}
1-e^{-(\beta x)^\alpha} & x\geq 0
\\
0 & x< 0
\end{cases}
\\
&\text{Střední hodnota: } &&\E X = \frac{1}{\beta} \Gamma\left(1+\frac{1}{\alpha}\right)
\\
&\text{Rozptyl: } &&\var X = \frac{1}{\beta^2} \left\lbrace\Gamma \left(1+\frac{2}{\alpha}\right)-\left[\Gamma\left(1+\frac{1}{\alpha}\right)\right]^2\right\rbrace
\\
\intertext{\subsection{Gama rozdělení}}\label{priloha:gammadist}
&\text{Značení: } &&X\sim \Gamma(\alpha,\;\beta)&&
\\
&\text{Parametry: } &&\alpha,\; \beta > 0
\\
&\text{Nosič: } &&X \in (0,\infty)
\\
&\text{Hustota: } &&f(x)=
\begin{cases}
\frac{\alpha^\beta}{\Gamma(\beta)}x^{\beta-1}e^{-\alpha x} & x>0
\\
0 & x\leq 0
\end{cases}
\\
&\text{Střední hodnota: } && \E X = \frac{\beta}{\alpha}
\\
&\text{Rozptyl: } && \var X = \frac{\beta}{\alpha^2}
\end{flalign}

Answer 1

From the images you show, I would suggest to use a tabular with a fixed width instead. This will allow you to break for things like subsections:
\documentclass[12pt,fleqn]{article}
\usepackage{amsmath}
\usepackage{array}
\begin{document}
\subsection{First part}
\noindent%
{%
\abovedisplayskip=-\baselineskip
\belowdisplayskip=-.5\baselineskip
\begin{tabular}{#{}p{.3\textwidth}#{}p{.7\textwidth}#{}}
First equation: & \begin{equation} a+b+c=d \end{equation}\\
Second equation: & \begin{equation} a+b+c=d \end{equation}\\
\end{tabular}
}
\subsection{Second part}
\label{sub:1}
\noindent%
{%
\abovedisplayskip=-\baselineskip
\belowdisplayskip=-.5\baselineskip
\begin{tabular}{#{}m{.3\textwidth}#{}m{.7\textwidth}#{}}
Next equation: & \begin{equation} a+b+c+45867+ddlk=d \end{equation}\\
Another equation: & \begin{equation} a+b+c+sdfsdf+565=d \end{equation}\\
\end{tabular}
}
Here alignment is working, but labeling not. Second part is \ref{sub:1}. It referes to 3th equation instead of subsection.
\end{document}