Question

Assume that y varies inversely with x. If y=7 when x=2/3, find y when x=7/3

Answer 1

When y varies inversely with x, we have $y= \frac{k}{x}$

We first find the value of k

When y = 7 and x = 2/3, then

$y= \frac{k}{x}$
$7= \frac{k}{ \frac{2}{3} }$
$7( \frac{2}{3})=k$
$k= \frac{14}{3}$

Now we have k = 14/3, we can work out y when x = 7/3

$y= \frac{k}{x}$
$y= \frac{14/3}{7/3}$
$y= \frac{14}{7}$
$y=2$