이렇게 하면 되나요 ??

% !TEX TS-program = pdflatex

% !TEX encoding = UTF-8 Unicode

 

\documentclass[11pt,leqno]{article} % use larger type; default would be 10pt

 

\usepackage{amsmath}

 

\begin{document}

 

\begin{equation}

\begin{split}

& g(R_{\xi} (Y), SX) -g( R_{\xi} (X), SY) \\

= \;\;& g(A^3\xi, Y)g(A\xi, X) -g(A^3 \xi, X)g(A\xi, Y) \\

& - g(A^2 \xi,Y)g(hA\xi -c\xi,X) +g(A^2\xi, X)g(hA\xi -c\xi, Y) \\

& -ch(g(A\xi, Y)\eta (X) - g(A\xi,X)\eta (Y))

\end{split} \tag{3.1}

\end{equation}

 

\end{document}