Question

If y varies directly as x and inversely as z^2, and y=3 when x=2 and z=4, what is the value of x when y=9 and z=4?

Answer 1

`3/2`

Explanation:

`y=kx/z^2` and (2, 3, 4) lies on this surface, So,

`k=((3)(4^2))/(2)=24`. The equation to the surface is

`x=1/24yz^2` and

`x = 1/24(9)(4)=3/2`, when `y = 9 and z = 4`.