[LaTex] line number in article model with equation (math environment)

https://tex.stackexchange.com/questions/25784/why-doesnt-lineno-number-a-paragraph-when-it-is-followed-by-an-indented-equatio

https://texblog.org/2012/02/08/adding-line-numbers-to-documents/

In case, when the paragraph includes equation with math mode, the line number does not allocate in this paragraph. 

To show the line number properly we have to include the following package.

1 2	\usepackage[displaymath, mathlines]{lineno} \linenumbers

And then, use following lines for equations.

1 2 3 4 5 6

\begin{linenomath*}     \begin{equation}         \dot{a} &=& 2a+5b \\         \dot{b} &=& a b     \end{equation} \end{linenomath*}