Question: I would like to have the words 'to mean' and the following mathematical statement to be on the same straight line. Thank you very much! 

```
    \documentclass[11pt,a4paper]{article}
    \usepackage{blindtext}
    \usepackage{mathtools}
    \DeclareMathOperator{\sgn}{sgn}
    \begin{document}
    \begin{flalign*}
    3=+1+1+1
    \end{flalign*}
    to mean
    \begin{flalign*}
    (+1+1+1)=+1+1+1,
    \end{flalign*}
    \end{document}

```

Answer: 
Try this.

```
\documentclass[11pt,a4paper]{article}
\usepackage{mathtools}
\begin{document}
\begin{flalign*}
&3=+1+1+1   & \\
\intertext{to mean}
&(+1+1+1)=+1+1+1,&
\end{flalign*}
\end{document}

```

![alignment](https://i.stack.imgur.com/ztBD1.png)
your code should be

```
\documentclass[11pt,a4paper]{article}
\usepackage{mathtools}
\begin{document}
\begin{align*}
3 &=+1+1+1   \\
\intertext{to mean}\\
(+1+1+1) &=+1+1+1,
\end{align*}
\end{document}

```

![intertextalign](https://i.stack.imgur.com/yRM0g.png)