方程式之间的垂直间距太大

Question

我的多个方程式之间的垂直间距太大，我该如何减小它？每个方程式都必须有一个单独的标签。

以下是我的序言：

\documentclass[11pt,openany]{mitthesis}
\usepackage[a4paper, margin=1in, twoside, openright]{geometry}
\usepackage[utf8]{inputenc}
\usepackage{graphicx}
\usepackage[export]{adjustbox} %ramme rundt bilder
\usepackage{fancyhdr}
\usepackage[nottoc, notlot, notlof]{tocbibind}
\usepackage[hyphens]{url}
\usepackage[hidelinks]{hyperref}
\usepackage[super,square]{natbib}
\usepackage{booktabs}
\usepackage{pdfpages}
\usepackage[labelfont=bf, font=small, labelsep=period]{caption}
\usepackage{longtable}                    % For lange tabeller
\usepackage{setspace}
\setstretch{1.15}
\usepackage{color,soul} %highlighting
\usepackage{float}
\usepackage{enumitem}   %lister
\setlist{noitemsep}     %ingen vertical spacing i liste
\usepackage[version=4]{mhchem} %kjemi-formler
\usepackage{tabularx} %hindre for brede tabeller
\usepackage[none]{hyphenat} %fjern automatiske bindestreker
\usepackage{mathtools} %matte

\usepackage[utf8]{inputenc} % Required for inputting international characters
\usepackage[T1]{fontenc} % Output font encoding for international characters

\usepackage[bottom]{footmisc}   %footnote
\usepackage{array}
\usepackage{ragged2e} %tabeller (flush)
\usepackage[]{bm}
\usepackage{perpage}

\MakePerPage{footnote}

代码如下：

This is some text before the equations:
\begin{equation}
    a = b
    \label{eq:1}
\end{equation}

\begin{equation}
    b = c
    \label{eq:2}
\end{equation}

\begin{equation}
   c = r
   \label{eq:3}
\end{equation}

The spacing is fine if I only have one equation:

\begin{equation}
    x = y
\end{equation}

Some text some text some text some text some text some text some text some text some text some text some text some text some text some text some text some text...\\

以及pdf：

Answer 1

由于您加载了mathtools，请使用gather环境：

\begin{gather}
    a = b
    \label{eq:1}\\
    b = c
    \label{eq:2}\\
   c = r
   \label{eq:3}
\end{gather}

或者align如果你想要...一些对齐：

\begin{align}
    a & = b
    \label{eq:1}\\
    b & = c + d + e\label{eq:2}\\
   c & = r
   \label{eq:3}
\end{align}