I learned to to solve equations that have a negative exponent.

Expressions such as this:

You apply these sort of expressions when you are solving various equations. This is how you apply it. 

Since it is an exponent that is negative you put it over one because its less then one. And to solve this:    you just have to solve what the exponent is, so 

Some challenges are if the coefficient is a fraction such as: 
 An easy way to get around this is simply switcing the numbers around like this : because it means the same thing.