I trying to align a programming model using eqnarray but the command \tag do not work with it, I could use align instead but the alignment is right for the first column and left for the second column. 

So what I want to do is use the eqnarray alignment (which is right for the first column and centered for the second column) with align.

This is how both commands look like:

[![enter image description here](https://i.stack.imgur.com/b7Aeh.png)](https://i.stack.imgur.com/b7Aeh.png)