# Assume y varies inversely as x, if y=-5 when x=9, how do you find y when x=6?

Jun 23, 2017

$y = - 7 \frac{1}{2}$

#### Explanation:

Here $y \propto \frac{1}{x}$

or $y = k . \frac{1}{x}$ ...........(i) put y = -5 & x = 9, we get

$\Rightarrow - 5 = k . \frac{1}{9}$

$\Rightarrow k = - 45$

Now put the value of k = -45 and x = 6 in (i), we get

$\Rightarrow y = - 45. \frac{1}{6}$

$\Rightarrow y = - 7 \frac{1}{2}$