How can I flush left text in the align environment?

Question

I have the following code:

\begin{align*}
m^+\cdot k^+ &= m^+\cdot k+m^+ &\text{by M2}\\
&= m\cdot k+k+m^+ &\text{since $k\in B$}\\
&= m\cdot k+(k+m^+) \\
&= m\cdot k+(k^{+}+m) &\text{by the second result}\\
&= m\cdot k+m+k^+ &\text{commutativity of addition}\\
&= m\cdot k^{+}+k^+ 
\end{align*}

but the text is all flushed right, but I would prefer it to be flush left to be closer to the actual equations.

Is there an easy fix for this? Thanks.

Answer 1

\documentclass{article}
\usepackage{amsmath}
\begin{document}

\begin{align*}
m^+\cdot k^+ &= m^+\cdot k+m^+   &&\text{by M2}\\
             &= m\cdot k+k+m^+   &&\text{since $k\in B$}\\
             &= m\cdot k+(k+m^+) \\
             &= m\cdot k+(k^{+}+m)&& \text{by the second result}\\
             &= m\cdot k+m+k^+    &&\text{commutativity of addition}\\
             &= m\cdot k^{+}+k^+ 
\end{align*}

\end{document}