Chapter 7 - Exponents and Exponential Functions - 7-5 Division Properties of Exponents - Practice and Problem-Solving Exercises - Page 445: 77

$\frac{y^{6}}{256x^{2}}$

=$(\frac{(4x)^{2}y}{xy^{4}})^{-2}$ =$(\frac{16x^{2}y}{xy^{4}})^{-2}$ =$(\frac{16x^{2-1}y^{1-1}}{x^{1-1}y^{4-1}})^{-2}$ =$(\frac{16x}{y^{3}})^{-2}$ =$(\frac{y^{3}}{16x})^{2}$ =$\frac{y^{6}}{256x^{2}}$