Question

Z varies jointly with x and y.

When x = 2 and y = 3, z = 60.

What is the value of z when x = 4 and y = 9?

Answer 1

Suppose that z varies jointly with x and y, and y = 3 when x = 2 and z = 30. What is z when x = 9 and y = 4? Use the step-by-step process you learned to solve this problem.

Step 1: Set up the correct type of variation equation.

z =

✔ kxy

Step 2: Determine the constant of variation.

k =

⇒ 5

Step 3: Determine the missing value.

z =

⇒ 180

Z=kxy k=5 z=180

Explanation:

Answer 2

First, let's find "k" the constant of variation:

z= k.x.y (since z varies jointly with x and y)

60 =k.(2).(3) → 60 = 6k and k =10, So z = 10x.y

z= 10(4)(9) = 10(36) and z = 360