Find the equation of variation in which y varies jointly as x and z and y=8, x=4 and z=2

if a varies directly with b, then it means

a = k*b

If y varies jointly as x & z, then it means y = k * x * z

So, if 8 = k * 4 * 2

Then k = 1, and y = x*z

To find the equation of variation in which y varies jointly as x and z, we can write it as:

y = k * x * z

Here, k is the constant of variation.

Given that y = 8, x = 4, and z = 2, we can substitute these values into the equation:

8 = k * 4 * 2

Simplifying the equation, we have:

8 = 8k

Dividing both sides of the equation by 8, we find:

k = 1

Therefore, the equation of variation in which y varies jointly as x and z is:

y = x * z

To find the equation of variation, we need to determine the constant of variation. In this case, the problem states that y varies jointly as x and z. This means that y is directly proportional to both x and z.

To find the constant of variation, we can set up a proportion using the given values:

y = kxz

Substituting the given values:

8 = k * 4 * 2

Simplifying:

8 = 8k

Solving for k:

k = 1

Now that we have the constant of variation, we can write the equation of variation as:

y = xz

So, the equation of variation is y = xz.