答案1
欢迎!本网站的目的不一定是将屏幕截图转换为 LaTeX 代码,但由于这是您的第一个问题,因此这里有一些可能朝着正确方向发展的内容。(请注意,我不知道是什么,Pr
所以有两种不同的解释。)
\documentclass{article}
\usepackage{amsmath}
\usepackage{mleftright}
\newcommand{\diff}{\mathop{}\!\mathrm{d}}
\mleftright
\begin{document}
\begin{multline*}
\frac{\diff}{\diff A}\left(\frac{\diff A}{\diff t}\right)+
\frac{\diff}{\diff B}\left(\frac{\diff B}{\diff t}\right)+
\frac{\diff}{\diff C}\left(\frac{\diff C}{\diff t}\right)\\
=
\frac{\diff}{\diff A}\bigl(P\,r\,(B-A)\bigr)
+\frac{\diff}{\diff B}\bigl(r\,B-B-A\,C\bigr)
+\frac{\diff}{\diff C}\bigl(-b\,C+A\,B\bigr)
\end{multline*}
or
\begin{multline*}
\frac{\diff}{\diff A}\left(\frac{\diff A}{\diff t}\right)+
\frac{\diff}{\diff B}\left(\frac{\diff B}{\diff t}\right)+
\frac{\diff}{\diff C}\left(\frac{\diff C}{\diff t}\right)\\
=
\frac{\diff}{\diff A}\bigl(\Pr(B-A)\bigr)
+\frac{\diff}{\diff B}\bigl(r\,B-B-A\,C\bigr)
+\frac{\diff}{\diff C}\bigl(-b\,C+A\,B\bigr)
\end{multline*}
\end{document}