how to move an align environment vertically to avoid blank line in enumerate

Question

I have an enumerate environment, where the text for each item is a single align environment. But this leaves a blank line since there is no text after the "\item".

Can I move the align environment up vertically? Without changing the spacing of the enumeration labels.

I've tried various combinations of \raisebox{}{}, \vspace{-number}, and adding "~" or "{}" to try and make it look like there is some text there. But these all seem to mess up the placement of the label.

Here is a MWE: I want the "x=1" to be at the same level as "(a)" and the "y=1" on the same level as (b).

Note that I do want \usepackage{enumitem} for other reasons.