Answer
$y = \frac{21}{x}$ or $xy = 21$
Work Step by Step
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.
$3\times7 = k$
$ 21 = k$
$k = 21$
Therefore, our equation for the inverse variation is $y = \frac{21}{x}$ or $xy = 21$
