# problem with equation length alignment

In fact, I have two equations but the numbering of the first one isn't parallel to the second one here is the code :

\documentclass[review]{elsarticle}

\usepackage{amssymb,amsmath,nccmath}

\begin{document}

\begin{align}

\dot{M}_{JS} &=\frac{\sigma X_s Z_r}{m_l u_{ab}}(\frac{-O_rS_s}{\sigma
R_L}-\dot{D}_{Eref}+\frac{sV_{AR}^2}{L_s}-\omega_rY_s+\frac{CL_m^2U_{JS}^4}
{\sigma S_L^2 R_L})-K.sin(sty)  \\

dot{N}_{JS} &=\frac{\sigma V_s V_r}{m_l u_{ab}}(\frac{-F_rG_s}{\sigma
CL_m^2U_{JS}^4} {\sigma S_L^2 R_L})
\end{align}
\end{document}


How can I make a good look of these equations

this rearrangement is based on my observation that your first and the second equation differ only in the last term:

\documentclass[review]{elsarticle}
\usepackage{amssymb,amsmath,nccmath}

\begin{document}
\begin{align}
\dot{N}_{JS}
& = \frac{\sigma X_s Z_r}{m_l u_{ab}}
\left(\frac{-O_rS_s}{\sigma R_L} - \dot{D}_{\mathit{Eref}} + \frac{sV_{AR}^2}{L_s} -
\omega_rY_s + \frac{CL_m^2U_{JS}^4}{\sigma S_L^2 R_L}\right)    \\
\dot{M}_{JS}
& = \dot{N}_{JS} - K\sin(sty)
\end{align}
\end{document}


edit:

after edited question we know, that equation is not so related as one conclude from the first question version. see, if this is what you looking for:

• in align environment are not aloved empty lines
• the meaning of K.sin(sty) is not clear. in my first solution i convert it to K\sin(sty)
• indices Eref and Oref are not set of variables ... just one. see what is more appropriated to you : \mathit{Oref} (as is in mwe below) or O\text{ref}

since the first equation is to long to fit in text width, one of possible solution (as shown in above image) is split it into two parts:

\documentclass[review]{elsarticle}
\usepackage{amssymb, mathtools, nccmath}

\begin{document}
\begin{align}
\dot{M}_{JS}
& = \frac{\sigma X_s Z_r}{m_l u_{ab}}
\left(\frac{-O_rS_s}{\sigma R_L} - \dot{D}_{\mathit{Eref}} + \right.    \notag\\
\left.\frac{sV_{AR}^2}{L_s} - \omega_rY_s + \frac{CL_m^2U_{JS}^4}{\sigma S_L^2 R_L}
\right) - K.sin(sty) \\
\dot{N}_{JS}
& = \frac{\sigma V_s V_r}{m_l u_{ab}}
\left(\frac{-F_rG_s}{\sigma H_L} - \dot{D}_{\mathit{Oref}} + \frac{MV_{AD}^2}{R_R} - \omega_qY_s + \frac{‌​CL_m^2U_{JS}^4}{\sigma S_L^2 R_L}\right)
\end{align}
\end{document}

• In fact it's just an example I want the full expressions as:\begin{align} \dot{M}_{JS} &=\frac{\sigma X_s Z_r}{m_l u_{ab}}(\frac{-O_rS_s}{\sigma R_L}-\dot{D}_{Eref}+\frac{sV_{AR}^2}{L_s}-\omega_rY_s+\frac{CL_m^2U_{JS}^4} {\sigma S_L^2 R_L})-K.sin(sty) \\ \dot{N}_{JS} &=\frac{\sigma V_s V_r}{m_l u_{ab}}(\frac{-F_rG_s}{\sigma H_L}-\dot{D}_{Oref}+\frac{MV_{AD}^2}{R_R}-\omega_qY_s+\frac{CL_m^2U_{JS}^4} {\sigma S_L^2 R_L}) \end{align} \end{documen – twimo Nov 26 '17 at 19:27
• please, edit your question and add/corect it as you stated in your comment. there more people will see, what you like to achieve. – Zarko Nov 26 '17 at 19:32
• @twimo, to my answer i add new solution considering edited question. maybe you like it. – Zarko Nov 26 '17 at 20:25