Chapter 9 - Section 9.4 - Variation and Problem Solving - Practice - Page 658: 3

The constant of variation is $18$. The inverse variation equation $y=\frac{18}{x}$.

$y=\frac{k}{x}$ $y=6;x=3$ $6=\frac{k}{3}$ $6\times3=\frac{k}{3}\times3$ $k=18$ $y=\frac{18}{x}$ The constant of variation is $18$. The inverse variation equation $y=\frac{18}{x}$.