Choose which rows in multi-line equation to assign numbers to

Question

If i do:

\begin{align}
    a = b \\
    b = c \\
    c = d \\
\end{align}

The output will be like:

(1)        a = b
(2)        b = c
(3)        c = d

If I use algin* instead. No row will be enumerated.

Is there a way to get the following output?

           a = b
           b = c
(1)        c = d

See for example http://tex.stackexchange.com/questions/65207/selective-numbering-of-equations-with-align and the linked questions. — Torbjørn T., Apr 15 '13 at 09:36

score 2 · Accepted Answer · edited Jul 15 '17 at 16:41

2

Rather than choosing which rows to enumerate you could let mathtools enumerate only the equations you reference.

\documentclass{article} 

\usepackage{mathtools}

\mathtoolsset{showonlyrefs}

\begin{document}

\begin{align}
  a = b \\
  b = c \label{eq:unused} \\
  c = d \label{eq:used} % Only this row will be enumerated as it's the
                        % only row that is referenced to.
\end{align}
\eqref{eq:used}

\end{document}

edited Jul 15 '17 at 16:41

ShreevatsaR

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answered Apr 15 '13 at 09:41

N.N.

36,163

That's exactly what I was looking for! Than you very much. – htellez Apr 15 '13 at 11:43
It didn't work as well as I expected.
All my \refs point to the first \subsubsection above them and no equation is being enumerated.
– htellez Apr 15 '13 at 11:48
@htellez Did you try eqref rather than ref? – N.N. Apr 15 '13 at 13:00
That was exactly the problem. Thank you so much. – htellez Apr 15 '13 at 19:15

Choose which rows in multi-line equation to assign numbers to

1 Answers1