Here is a thread that will give you some ideas
http://web2.0calc.com/questions/indices-especially-negative-indices
Basically if something is raised to a negative power, you swap it to the other side of the fraction line and change the negative index to a positive one.
Here is a thread that will give you some ideas
http://web2.0calc.com/questions/indices-especially-negative-indices
Basically if something is raised to a negative power, you swap it to the other side of the fraction line and change the negative index to a positive one.