Question

If x varies inversely as y, and x = 11 when y = 15, how do you find x when y = 3?

Answer 1

`x=55`

Explanation:

If `x` varies inversely as `y`, then that means:

`y=k/x`

Let's multiply both sides of the equation by `x` to find `k`.

`k=xy`

Plugging the numbers in:

`k=(11)(15)=165`

Now, we go back to the original equation and solve for x:

`y=k/x`

`x=k/y`

Finally, plug `y=3` and `k=165`:

`x=165/3`

`x=55`