how to concat fixnum and string in rails?

i want to contat my static id + looping primary key id

 <% @user.each do |employee| %>
 <td><%=employee.username%></td>
   <td> <%=link_to 'activate',activate_path(id:employee.id), method: :patch ,id:"activate"+"<%=employee.id%>".to_s%></td>
     <% end %>