# Hiding tag in a subequations and align environment also centring

I need to hide tags inside subequations and align environments. I do not want to use \tag{}, the tag should be placed automatically when I typeset. Here it is,

\begin{subequations}
\begin{align}
\end{align}
\end{subequations}


It works but it is ugly. Also the equation tags are placed in the line after the equation which should be the same line. Any help would be appreciated.

• Why are you using an align environment but not providing any alignment points? – Mico Apr 14 '17 at 14:20
• @Mico, would you like to expand that what you just meant ? e.g. alignment points. – Meva Apr 14 '17 at 14:26
• Alignments points are provided by &. They're used in Zarko's answer to align the four = symbols. – Mico Apr 14 '17 at 14:56

I suppose, that you like to have something like this:

In your code sniped are all quads surplus. For text between equation in align environment is intended \intertext{...}. Use of align has sense if you with & determine anchors to which equations are aligned:

\begin{subequations}
\begin{align}
H(x,t) & = H_0 (x) + t H_1 (x) + t^2 H_2 (x) + ... ,
\intertext{with the dominant term being}
H_0    & = - F(x) + m_0 + (x - y)\theta _0 ,             \\
\intertext{and remaining orders}
H_1    & = m_1 + (x - y) \theta_1 ,                      \\
H_2    & = m_2 + (x - y) \theta_2 .
\end{align}
\end{subequations}