Make sure you are using bridged ethernet, this will insure your VM gets its own ip address.
Also make sure you configured your oracle xe to allow remote connection and administration.
Open a console windows in your linux session. Type ifconfig. What do you get as the ip address for your linux machine? call it <ip>, now open safari and use
http://<ip>:8080/apex as the address to connect to. You should see the oracle XE home administration login page.