The article Differences of powers that you've just created should be part of the preexisting article sum and difference of powers. The appropriate thing to do would be to move content as necessary and turn the new article into a redirect. Also, please learn latex (see also http://www.artofproblemsolving.com/Forum/viewtopic.php?t=123690 ) -- that way, other contributors can edit what you add.
Thanks. --JBL 20:04, 5 July 2008 (UTC)