# If y varies inversely as x, and y=14 when x=7, how do you find y when x=10?

Jun 13, 2018

$\frac{98}{10} = 9.8$
$y \propto \frac{1}{x} \implies y = C \cdot \frac{1}{x} = f \left(x\right)$
$14 = C \cdot \frac{1}{7} \implies C = 14 \cdot 7 = 98$
$f \left(10\right) = C \cdot \frac{1}{10}$