Question

Given that y varies inversely with x, if y=-5 when x=-6, find x when y=-2.5.

Answer 1

15

Explanation:

If y varies inversely as x, the two variables can be represented in an equation in the form

y

=

k

x

where

k

is some constant.

We are given that

y

=

5

when

x

=

6

. We can plug this into the above equation to find what

k

is:

5

=

k

6

30

=

k

Based on this we can create our equation:

y

=

30

x

And then find

x

when

y

=

2

:

2

=

30

x

2

x

=

30

x

=

15