Question

Write an equation describing the relationship of the given variables y varies jointly with x and z and when x=5 and z=9, y=90

Answer 1

Answer:

y=2xz

Explanation:

Given that y varies jointly with x and z, the equation of variation is given as:

$\begin{gathered} y=kxz \\ \text{where k is the constant of variation} \end{gathered}$

When x=5, z=9, and y=90:

$\begin{gathered} y=kxz \\ 90=k\times5\times9 \\ 90=45k \\ \text{Divide both sides by 45} \\ \frac{90}{45}=\frac{45k}{45} \\ k=2 \end{gathered}$

Therefore, an equation describing the relationship of the given variables is:

$y=2xz$