error docker machine

root@fernandotest:/# docker-machine create --driver virtualbox dev
Running pre-create checks...
(dev) You are using version 4.3.36_Ubuntur105129 of VirtualBox. If you encounter issues, you might want to upgrade to version 5 at https://www.virtualbox.org
Error with pre-create check: "This computer doesn't have VT-X/AMD-v enabled. Enabling it in the BIOS is mandatory"