# If y varies inversely with x. how do you find the inverse variation equation if x = -3 when y = 30?

Jun 17, 2016

#### Answer:

$x y = - 90$

#### Explanation:

If $y$ varies inversely as $x$ then
$\textcolor{w h i t e}{\text{XXX}} x \cdot y = k$ for some constant $k$

Since $x = - 3$ when $y = 30$
$\textcolor{w h i t e}{\text{XXX}} \left(- 3\right) \cdot \left(30\right) = k$

$\textcolor{w h i t e}{\text{XXX}} \rightarrow k = - 90$