## Algebra 1: Common Core (15th Edition)

An equation for inverse variation is $xy = 45$.
Use the general form of an inverse variation equation: $xy=k$ Substitute 6 for $x$ and 9 for $y$. $6.9=k$ $k=45$ Substitute 45 for $k$ in $xy = k$. An equation for the inverse variation is $xy = 45$.