Check out what this guy means:

( x / y )^5

That's 5 blobs of   ( x / y )   all multiplied together:

 ( x / y )^5 = x^5 / y^5

It's like the exponent is getting distributed to the top and to the bottom!

( x / y )^5 = x^5 / y^5

Here's the official rule:

( a^n / b^n ) = a^n / b^n