Question

If y varies inversely as x and y = -97 when x = 28 find y if x = 36.

Answer 1

Given:

$y\alpha\frac{1}{x}$

Introducing a constant 'k'

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

Substitute y = -97, x = 28

$\begin{gathered} -97=\frac{k}{28} \\ \therefore k=-97\times28=-2716 \end{gathered}$

Let us write out the relationship connecting y and x

$y=-\frac{2716}{x}$

Let us now solve for y if x = 36

$y=-\frac{2716}{36}=-75\frac{4}{9}$

Hence,

$y=-75\frac{4}{9}$