Chapter 11 - Rational Expressions and Functions - 11-6 Inverse Variation - Practice and Problem-Solving Exercises - Page 691: 31

$k = 256$ Therefore, our equation for the inverse variation is $y = \frac{256}{x}$ or $xy = 256$

Our equation for an inverse variation is $y = \frac{k}{x}$ or $xy = k$. We will use the second form of the equation to solve for k. $-32\times-8 = k$ $ 256 = k$ So, $k = 256$ Therefore, our equation for the inverse variation is $y = \frac{256}{x}$ or $xy = 256$