Selective numbering of equations with align

Question

I have an align environment with 5 equations. I want 3 of them numbered, and the other 2 not numbered. I understand that there's other posts on the issue of selective numbering of those equations that are referred to in the body of the text, but that's different to what I'm trying to achieve.

I want the first three lines (equations) of the following to be numbered and the last two to be without numbering. Thanks.

\documentclass[a4paper,11pt]{article}
\usepackage[fleqn]{amsmath}
\begin{document}

\begin{align}
&R_{i,t} = \alpha_i  \\
&R_{i,t} = \beta_i  \\
&R_{i,t} = \gamma_i  \\
&\mathbb{E}[\epsilon_{it}]=0;\textrm{   } \textrm{Var}[\epsilon_{it}]=\sigma^2_{\epsilon_{i}}\\
&i \in \{1,2,...,N\};\textrm{   } t \in \{1,2,...,T\}
\end{align}

\end{document}

Answer 1

Just add \notag to the lines you don't want numbered.

But if you are using fleqn, you don't need align, you can use gather instead (the \notag works the same) and remove the &s:

\documentclass[a5paper,11pt]{article}
\usepackage[fleqn]{amsmath}
\usepackage{amsfonts}
\begin{document}

\begin{gather}
R_{i,t} = \alpha_i \notag \\
R_{i,t} = \beta_i \notag \\
R_{i,t} = \gamma_i \notag \\
\mathbb{E}[\epsilon_{it}]=0;\textrm{   } \textrm{Var}[\epsilon_{it}]=\sigma^2_{\epsilon_{i}}\\
i \in \{1,2,...,N\};\textrm{   } t \in \{1,2,...,T\}
\end{gather}

\end{document}

(You probably wanted the other lines numbered).