Then until you get used to cubes and higher exponents
just get rid of all exponents first and write 
as  and  as , etc.

Also break  into a product of primes
and write it as as 

So,

.

becomes

. 

Indicate the multiplication of the numerators and
the denominators so that you only have one
fraction:



Now cancel:



So all that's left is



and we write  as  and end up with



This method will always work, and you can use it
until you can see that it's quicker just to subtract
the exponents, which would amount to subtracting
the number of 's or 's which would 
cancel in the mathod shown above.

Edwin