I'm trying to properly align a simple linear Program: Right now I'm using
\usepackage{amsmath}
\begin{document}
\begin{equation*}
\begin{array}{r r c r c r}
\displaystyle \min &x_1 &+&x_2\\
\text{s.t.} & 10x_1& +&10x_2 &\leq &0\\
&111x_1 &+&x_2 &\geq &0\\
& x_1& &,x_2 & \geq & 0
\end{array}
\end{equation*}
\end{document}
But I would like to 'gather' the last constraint in such a way, that it is aligned to the right with all other 'x_2' but without the space between 'x_1' and ','. Is there a way to omit the space without interfering the other constraints?