How to number gathered equations using single number

Question

I want to number gathered equations, but single number for several equations. Following is the code I've used. But it results numbering both equations. I want to equations to be justified, not right aligned. Spilt and align environment right align the equations. Is there any way to do this?

\begin{gather}
\eta_{c1} P_{pv}(k) + \eta_{c2} P_{bat}(k) \leq P_{conG,rate} \\\
P_{grid} + P_{load} \geq -P_{conG,rate} 
\end{gather}

Answer 1

After \ you can put \nonumber this way you can avoid having both equations numbered

Answer 2

Here is a cleaner solution than using \nonumber. Using gathered or aligned environments inside an equation environment groups the equations and assigns one number to them. This is recommended by the amsmath user guide.

\documentclass{article}

\usepackage{amsmath}

\begin{document}

\begin{equation}
    \begin{gathered}
        \eta_{c1} P_{pv}(k) + \eta_{c2} P_{bat}(k) \leq P_{conG,rate}
        \\
        P_{grid} + P_{load} \geq -P_{conG,rate}
    \end{gathered}
\end{equation}

\begin{equation}
    \begin{aligned}
        \eta_{c1} P_{pv}(k) + \eta_{c2} P_{bat}(k) &\leq P_{conG,rate}
        \\
        P_{grid} + P_{load} &\geq -P_{conG,rate}
    \end{aligned}
\end{equation}

\end{document}