select multiple elements declared as variable

in the example below how to say a and b.show() instead of $('.lorem, .ipsum').show();

$(document).ready(function(){
var a = $('.lorem');
var b = $('.ipsum');
 $('.lorem, .ipsum').show();
//a and b.show();
});
.lorem, .ipsum{display:none;}
<script src="https://cdnjs.cloudflare.com/ajax/libs/jquery/3.3.1/jquery.min.js"></script>
<div class='lorem'>lorem</div>
<div class='ipsum'>ipsum</div>

Answer

You can use .add():

a.add(b).show();

The .add() method allows a selector string, or a jQuery object, one or more element node references, or an HTML string to be added to an existing jQuery object. Note that a new jQuery object is returned; the original a in the above example is unchanged.