Well, +/- is written as ± if you have that symbol available. And the symbol for -/+ is similar except the plus is on bottom. The first one is more commonly available because it is the mathematical "plus or minus". They are usually spoken as "plus over minus" or "minus over plus".
BTW, article talk pages are for discussing improvements to the article rather than asking questions. Bubba73 (talk), 02:21, 13 July 2008 (UTC)