adduser, so you can just say
adduser bperry X. openSUSE as well has Red Hat have
useradd, which is not the same. I had to use
usermod bperry -G X. The final outcome was
su -c usermod bperry -G vboxusers.
PS: I am probably the most incompetent person alive when it comes to women. So, women, do yourself a favor and never talk to me again, I will just embarrass myself. Thanks.