Answer
$x=\displaystyle \frac{kyz}{w^{2}}$
$y=\displaystyle \frac{xw^{2}}{kz}$
Work Step by Step
$x$ varies directly as $y:\qquad x=ky$
$x$ varies directly as $z:\qquad x=kz$
$x$ varies inversely as $w^{2} :\displaystyle \qquad x=\frac{k}{w^{2}}$
Combined (jointly): $\displaystyle \qquad x=\frac{kyz}{w^{2}}$
Solving for $y,$
(multiply both sides with $\displaystyle \frac{w^{2}}{kz})$
$\displaystyle \frac{xw^{2}}{kz}=y$
