Chapter 11 - Polynomial and Rational Functions - 11.1 Power Functions and Proportionality - Exercises and Problems for Section 11.1 - Exercises and Problems - Page 440: 24

$x=3$ when $y=8$

We are given that $y=6; x=4$ $y$ is inversely proportional to $x$. We can write $y=\dfrac{k}{x}~~~~(1)$ Plug $y=6; x=4$ in equation (1) to obtain: $6= \dfrac{k}{4} \implies k=24$ Thus, we have: $c=\dfrac{24}{x} ~~~~(2)$ Now, plug $y=8$ in Equation (2) to obtain: $x=\dfrac{24}{8} \implies x=3$ Therefore, we get $x=3$ when $y=8$.