You probably don’t want to do this, since backups are useful, especially when something goes wrong.
To avoid seeing backup files (and other “uninteresting” files) in
dired-x by adding the following to your init file
(see How do I set up an init file properly?):
(with-eval-after-load 'dired (require 'dired-x))
dired-x loaded, C-x M-o toggles omitting in each dired buffer.
You can make omitting the default for new dired buffers by putting the
following in your init file:
(add-hook 'dired-mode-hook 'dired-omit-mode)
If you’re tired of seeing backup files whenever you do an ‘ls’ at
the Unix shell, try GNU
ls with the ‘-B’ option. GNU
ls is part of the GNU Fileutils package, available from
https://ftp.gnu.org and its mirrors (see Where can I get other up-to-date GNU stuff?).
To disable or change the way backups are made, see Backup Names in The GNU Emacs Manual.
You can control where Emacs puts backup files by customizing the
backup-directory-alist. This variable’s value
specifies that files whose names match specific patterns should have
their backups put in certain directories. A typical use is to add the
("." . dir) to force Emacs to put all
backup files in the directory dir.