Question

If y varies inversely as x and y = 6 when x = 18, then how do you find x when y = 10?

Answer 1

`x=10.8`

Explanation:

If `y` varies inversely as `x` then
`color(white)("XXX")xy =c color(white)("XXX")" for some constant " c`

Given `(x,y)=(18,6)` is a solution pair to this relation
`color(white)("XXX")(18)(6) =c`

`rarrcolor(white)("XXX")c = 108`

`rarr` The relationship is
`color(white)("XXX")xy =108`

therefore when `y=10`
`color(white)("XXX")x(10) =108`

`rarrcolor(white)("XXX")x=10.8`