Laravel authentication routing after click login button

I have 2 laravel application inside var/www/html directory .In the address bar , if we type localhost/first , then laravel authentication will be displayed and the URL is http://localhost/first/public/auth/login .But after i click submit button the URL will become http://localhost/auth/login and it shows a error of The requested URL /auth/login was not found on this server.

can you suggest me y it goes wrong.what i need is i want the URL in address bar as it is..

via Chebli Mohamed