# Numbering equations in an optimization problem

I am trying to assign numbers to my equations in an optimization problem, however Latex keeps giving one number for the single problem. I have checked multiple sources for any advice, but I have yet to find one satisfactory.

The model is as follows:

\begin{aligned} & \underset{k=1, t\epsilon T, p\epsilon P}{\text{Max}} & &\sum_{p\epsilon P}(a_{p,k,t}x_{p,t})+\sum_{t=1}^{T}{(1+r)}^{T-t}y_t \\ & \text{subject to} & & f\sum_{ p\epsilon P}x_{p,t}+y_t=B_t , & \forall t \\ &&& k\geq m_k , & \forall k \\ &&& p_i\geq g_{pi,pj} , & \forall i \vee j && j \neq i \\ &&& \sum_{p\epsilon P}\sum_{t\epsilon T} (a_{p,k,t}x_{p,t})+\sum_{t=1}^{T}{(1+r)}^{T-t}y_t \geq B_F \\ \end{aligned}


I synthesize that the problem is due to me using only one equation format, but I've tried with several, but that only gave me errors.

• Welcome to TeX.SX! You can have a look at our starter guide to familiarize yourself further with our format. Sep 21, 2017 at 15:04

Do you mean to use the align environment instead of the aligned environment? aligned creates only one equation number for the whole environment. align creates a separate equation number for each new line in the environment.

If you want to omit numbering on specific equations, you can do so with the \nonumber command.

\documentclass{article}
\usepackage{amsmath,amssymb,amsfonts,amsthm}
\title{Equation Numbering}
\begin{document}
\maketitle

\begin{align}
& \underset{k=1, t\epsilon T, p\epsilon P}{\text{Max}}
& &\sum_{p\epsilon P}(a_{p,k,t}x_{p,t})+\sum_{t=1}^{T}{(1+r)}^{T-t}y_t  \\
%
& \text{subject to}
& & f\sum_{ p\epsilon P}x_{p,t}+y_t=B_t , & \forall t \\
%
&&& k\geq m_k , & \forall k \nonumber \\
%
&&& p_i\geq g_{pi,pj} , & \forall i \vee j && j \neq i \nonumber \\
%
&&& \sum_{p\epsilon P}\sum_{t\epsilon T}
(a_{p,k,t}x_{p,t})+\sum_{t=1}^{T}{(1+r)}^{T-t}y_t \geq B_F
\end{align}
\end{document}


Here is a solution with alignat:

    \documentclass{article}
\usepackage{mathtools}
\DeclareMathOperator{\Max}{Max}

\begin{document}

\begin{alignat}{3}
& \underset{\substack{k=1, t ∈ T, \\ p ∈ P}}{\Max}\,
\mathrlap{∑_{p ∈ P}(a_{p,k,t}x_{p,t})+∑_{t=1}^{T}{(1+r)}^{T-t}y_t} \\
& \text{subject to}
& \quad & f∑_{ p ∈ P}x_{p,t}+y_t=B_t , & & \quad ∀ t \\
& & & k\geq m_k , & & ∀ k \\
& & & p_i\geq g_{pi,pj} , & & ∀ i ∨ j ,\quad j ≠ i \\
& & & ∑_{p ∈ P}∑_{t ∈ T} (a_{p,k,t}x_{p,t}) + \mathrlap{∑_{t=1}^{T}{(1+r)}^{T-t}y_t \geq B_F }
\end{alignat}

\end{document}