If y varies inversely as x and y = 9 when x = 14, how do you find why when x = 6?

Mar 22, 2016

$y = 21$

Explanation:

Let $k$ be a constant

$x = k \times \frac{1}{y}$

$\implies k = x y = 9 \times 14 = 126$

$\implies x = \frac{126}{y}$

So $y = \frac{126}{x}$

At $x = 6 \text{ we have }$

$y = \frac{126}{6} = 21$