Question

If y varies inversely as x and y = 725 when x = 20, how do you find x when y is 50?

Answer 1

`x=290` when `y=50`

Explanation:

When you are told that `y` varies inversely as `x`, that means that

`x*y=k`

where `k` can be any single number. If you plug in the initially given numerical values for `x` and `y` you have

`20*725=14500`

So your `k`-value becomes `14500`. Now you can say that, for this particular relation

`xy=14500`

If you want to know your `x`-value when `y=50`, you can plug `50` in for `y` and solve for `x`.

`x*50=14500`

so

`x=14500/50`

meaning that

`x=290`.