I think you have misunderstanding/misconception here.
The ajax call can be made after the PHP (Laravel) renders the HTML file and load it into your browser. Then the ajax call is done in your browser, not in the server. So you cannot asign a PHP variable from client/browser side.
What you can do is that you can create a JavaScript variable inside blade file (which is not recommended btw (https://stackoverflow.com/a/23740549/1331040)):
var urlApplied = {{$url['applied']}};
Then hide/show the content based on ajax response:
jQuery.ajax({
...
success: function(data) {
urlApplied = data.response; // or whatever the property you have instead of 'response'
}
});
Since you haven't provided the content you want to hide/show, I cannot give more specific hide/show logic but hope this gives you a clue.
But I strongly suggest you to reconsider the logic by decoupling the browser and client side flows (you can read the answers in the link I shared above).