Find an equation of variation in which the following are true.
-$y$ varies directly as $x$ and inversely as $z$, and $y = 18$ when $x = 2$ and $z = 9$.
A) $y = \frac { 81 x } { z }$
B) $y = \frac { 85 x } { z }$
C) $y = 84 x z$
D) $y = \frac { 80 z } { x }$

Question

Quizplus · Accepted Answer

The equation for $y$ varies directly as $x$ and inversely as $z$ is $y = k\frac{x}{z}$, where $k$ is the constant of variation. Substituting $x = 2$, $y = 18$, and $z = 9$ into the equation gives $18 = k\frac{2}{9}$. Solving for $k$ gives $k = 81$. Therefore, the equation is $y = \frac{81x}{z}$.

Find an Equation of Variation in Which the Following Are yyy

Find an Equation of Variation in Which the Following Are $y$