Math & Science ⇒ subequation with equation

[samwell187]

is it possible to have a "master" equation and then subequations below it? So in the example below, I'd like the number of equation that says no~letter to be (1), and then a to be (1a) and b to be (1b)

Code: Select all

\begin{subequations}
hello
\beq
no~letter
\eeq
hi
\beq
a
\eeq
hi again
\beq
b
\eeq
\end{subequations}

[Ijon Tichy]

Your code snippet is somehow unclear. A minimal working example would be better. However using amsmath or mathtools (which uses amsmath) you can do:

Code: Select all

\documentclass{article}

\usepackage{mathtools}

\begin{document}
\begin{subequations}
\begin{align}
  a&=b\tag{\theparentequation}\\% Set another tag than the automatic one.
  b&=c\\
  c&=d
\end{align}
\end{subequations}
\end{document}

See the amsmath manual section 3.1 for more information about \tag and section 3.11.3 about counter parentequation.

[samwell187]

thanks! this is what i needed
(sorry, \beq and \eeq mean \begin and \end{equation} for me )