Question

use the rules of exponents to evaluate and simplify the following expression. (x*y)^-3

Answer 1

When something is put to the negative power, this transformation happens:  
  
$x^-y = \frac{1}{x^y}$  
  
Now, apply this to your question;  
  
$(xy)^-3 = \frac{1}{(xy)^3}$  
  
Simplify the expression:  
  
$\frac{1}{x^3 y^3}$