Question

Suppose that y varies inversely with x. Use the information to find k, and then choose the equation of variation. x = 13 when y = 100.

Answer 1

To solve this problem you must apply the proccedure shown below:

1. You have that
`y` varies inversely with
`x` and when
`x=13` the value of
`y` is
`y=100`.

2. Therefore, you can write the following expression, where
`k` is the constant of proportionality:

`y=(k)/(x)`

3. Solve for the constant of proportionality and substitute the values to calculate it:

`k=yx\\ k=(100)(13=\\ k=1300`

4. The equation is:

`y=(1300)/(x)`

The answer is:
`k=1300\\ y=(1300)/(x)`