JSFiddle - React, Tailwind, and code Playground
HTML
<form>
<textarea type="text" name="1"></textarea>
<textarea type="text" name="2"></textarea>
<textarea type="text" name="3"></textarea>
<textarea type="text" name="4"></textarea>
<select name="sel_1">
<option>1</option>
<option>2</option>
<option>3</option>
</select>
<button type="submit" disabled="disabled">Сохранить</button>
</form>
JavaScript
$(document).ready(function(){
$('textarea').keyup( function() {
$('button').removeAttr("disabled");
});
$('select').change(function() {
$('button').removeAttr("disabled");
})
});