Describe how you would simplify the given expression.

Deal with the expression in the parentheses first.

20 / 5 = 4
x^5 / x^-3  = x^8
y^2/y^7 = y^-5  so we have

(4x^8 y^-5)^-3

= 1/64 * x^-24 y^15     which can be written as:_

    y^15
-----------
  64 x^24