对方程数组进行编号

Question

我想以方程数组模式来做这件事。与图中完全相同。

Answer 1

像这样吗？

\documentclass{article}
\usepackage{amsmath}
\begin{document}
\begin{subequations}
\begin{gather}
\min z_1  = \sum_{i=1}^{m} \sum_{j=1}^{n} \sum_{k=1}^{l} \tilde{c}_{ijk}x_{ijk} \\
\min z_2  = \sum_{i=1}^{m} \sum_{j=1}^{n} \sum_{k=1}^{l} \tilde{t}_{ijk}y_{ijk} \\
\intertext{subject to,}
 \sum_{j=1}^n\sum_{K=1}^l x_{ijk} \leq a_i, \qquad i=1,2,3,\dots,m, \\
 \sum_{i=1}^m\sum_{K=1}^l x_{ijk} \geq b_i, \qquad j=1,2,3,\dots,n, \\
 \sum_{i=1}^n\sum_{j=1}^n x_{ijk} \leq e_k, \qquad k=1,2,3,\dots,l, \\
\intertext{$x_{ijk} \geq 0$, and}
y_{ijk} = \begin{cases} 1, & \text{if}\ x_{ijk} > 0; \\ 0, & \text{otherwise}\end{cases}
\end{gather}
\end{subequations}
for all $i, j, k$.
\end{document}