Aligning equation on the left

I need to align equations of the left.

I wrote the following according to this topic : Align equation left

\begin{flalign}
p(1-p)^2 (\alpha |001\rangle + \beta |110 \rangle).hc +p^2(1-p) (\alpha |110\rangle + \beta |001 \rangle).hc& \\ \rightarrow X_3 \left( p(1-p)^2 (\alpha |001\rangle + \beta |110 \rangle).hc +p^2(1-p) (\alpha |110\rangle + \beta |001 \rangle).hc \right) X_3& \\
= p(1-p)^2 (\alpha |000\rangle + \beta |111 \rangle).hc +p^2(1-p) (\alpha |111\rangle + \beta |000 \rangle).hc&
\end{flalign}

But the render is not good, and I have numerotations on the right : The render is not good because as you can see the first line is not left aligned.

I don't understand what I did wrong (because in the topic associated they basically just use flalign as I did...??)

• Do you want to align on the left all equations, or only some? Jan 18 '19 at 12:31
• @StarBuck I do noy understand your question. To me the equations you show are aligned on the left. Jan 18 '19 at 12:33
• @Denis the first line starts more on the right than the second line. So the first line is not aligned on the left Jan 18 '19 at 12:34
• @Bernard all of them but actually I would be interested to know how I can chose a given alignment for specific equations as well Jan 18 '19 at 12:35
• @StarBuck Sorry. I tend to confuse my left and my right ;-). Jan 18 '19 at 12:56

Does something like that would suit you ?

\documentclass[a4paper]{article}
\usepackage[fleqn]{amsmath}
\usepackage{mathtools}
\begin{document}
\begin{equation}
\begin{aligned}
&a = k\\
&b = k = l\\
&c = k = l = h
\end{aligned}
\end{equation}

\begin{equation}
d = k = l = h = m
\end{equation}

\end{document} • It would be perfect if I just dont have 3 numerotations ( (1),(2),(3) ) for the same align Jan 18 '19 at 13:04
• @StarBucK, You can put a \nonumber on the lines you want unnumbered. Another tip, the subequations package Jan 18 '19 at 13:16
• @StarBucK See my edit. If you want no equation number at all for the align replace equation by equation* Jan 18 '19 at 13:35

Will the following be good enough?

\documentclass{article}
\usepackage{amsmath, nccmath}
\usepackage{geometry}

\begin{document}

Some text. Some more text. Some more text. Some more text. Some more text. Some more text. Some more text. Some more text. Some more text. Some more text. Some more text.

\begin{align}
\nonumber
&p(1-p)^2 (\alpha |001\rangle + \beta |110 \rangle).hc +p^2(1-p) (\alpha |110\rangle + \beta |001 \rangle).hc \\
\nonumber
&\rightarrow X_3 \left( p(1-p)^2 (\alpha |001\rangle + \beta |110 \rangle).hc +p^2(1-p) (\alpha |110\rangle + \beta |001 \rangle).hc \right) X_3 \\
\nonumber
&= p(1-p)^2 (\alpha |000\rangle + \beta |111 \rangle).hc +p^2(1-p) (\alpha |111\rangle + \beta |000 \rangle).hc
\end{align}
\end{document}