Write an equation to describe the variation. Use k for the constant of proportionality.

x varies directly as the square of y and inversely as z

I think it is x=ky^2z

x=kyz

The equation to describe the variation is:

x = k * (y^2) / z

To represent the direct variation between x and the square of y, we can write:

x = k * y^2

To incorporate the inverse variation between x and z, we can add an inverse proportionality term:

x = k * y^2 / z

In this equation, "k" represents the constant of proportionality, while "^2" denotes the square of y.