This article presents two ways to split long equations into multiple lines with and without alignment.

1. Split equations

Use multline or split provided by amsmath package.

• Use multline to split equations without alignment (first line left, last line right)
• Use split to split equations with alignment

Here are examples:

Fig. 1: Illustrated examples to split equations.

For more info, refer to User’s Guide for the amsmath Package.

2. The source code

The corresponding source code is as follows:

(i).Use equation:
\begin{equation}
1+2+3+4+8x+7=1+2+3+4+4x+35 \\
\Rightarrow x=7
\end{equation}

(ii).Use \emph{multline} to split equations without alignment:
\begin{multline}
1+2+3+4+8x+7=1+2+3+4+4x+35 \\
\Rightarrow x=7
\end{multline}

(iii).Use \emph{split} to split equations with alignment
\begin{equation}
\begin{split}
1+2+3+4+8x+7 & =1+2+3+4+4x+35 \\
& \Rightarrow x=7
\end{split}
\end{equation}

References:
[1] StackExchang TeX-LaTeX: How can I split an equation over two lines