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

y=2xz

Step-by-step 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*5*9 \\ 90=45k \\ \text{Divide both sides by 45} \\ (90)/(45)=(45k)/(45) \\ k=2 \end{gathered}`

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

`y=2xz`