installation Of Oracle 18c in silent mode

This installation is for:

Oracle Linux Server release 7.7
Oracle Database 18c Enterprise Edition Release 18.0.0.0.0

Disabling SELINUX:

[root@dba18 ~]# vi /etc/selinux/config
[root@dba18 ~]# cat /etc/selinux/config
SELINUX=disabled
SELINUXTYPE=targeted

Disabling the Firewall:

[root@dba18 ~]# service firewalld stop
Redirecting to /bin/systemctl stop firewalld.service
[root@dba18 ~]# systemctl disable firewalld
Removed symlink /etc/systemd/system/multi-user.target.wants/firewalld.service.
Removed symlink /etc/syst