# The variables x and y vary inversely. How do you write an equation that relates x and y given x = 15, y = 5?

Mar 14, 2017

$y = \frac{75}{x}$

#### Explanation:

$y = \frac{k}{x}$, where $k$ is a constant

Substitute in $x = 15 , y = 5$,
$5 = \frac{k}{15}$
$k = 75$

Hence, $y = \frac{75}{x}$