x -1

DO you mean to raise 'x' to the -1 power.....that would be called a superscript or exponent....that is a function of you keyboard or character set in your computer....most of us just do this:   x^(-1)

x  ¹      xˉ¹       Takes a lot of work to copy the superscripts from your character map.    Search for 'character map' on your computer and you can copy and paste all sorts of symbols.  Some computers allow you to 'map' keys for the special characters, but again it's easier to just  x^(-1)