Could you please help me with the following question?

Find the variation equation for the variation statement.
31. z varies jointly as y and the cube of x; z=96 when x=2 and y=6 (I don't understand this one. My answer choices are: a.y=2x^3y,b.y=2xy^3, c.y=-2x^3y, or d. y=-2xy^3)

Could you please help me with the following question?

Find the variation equation for the variation statement.
31. z varies jointly as y and the cube of x; z=96 when x=2 and y=6 (I don't understand this one. My answer choices are: a.y=2x^3y,b.y=2xy^3, c.y=-2x^3y, or d. y=-2xy^3)

To find the variation equation, we need to understand the concept of joint variation. In a joint variation, a variable varies directly with two or more other variables, raised to some powers.

In this case, we are told that "z varies jointly as y and the cube of x." This means that z is directly proportional to both y and the cube (third power) of x. Mathematically, we can write this as:

z = k * x^3 * y

Here, k represents the constant of variation.

To find the value of k, we can use the given information. It states that z is equal to 96 when x is 2 and y is 6. Substituting these values into the variation equation, we get:

96 = k * (2^3) * 6
96 = k * 8 * 6
96 = k * 48

Now, we can solve for k by dividing both sides of the equation by 48:

k = 96 / 48
k = 2

Substituting the value of k back into the variation equation, we get:

z = 2 * x^3 * y

Comparing this equation to the answer choices, we see that the correct answer is (a) y = 2x^3y.

So, the variation equation for the given variation statement is y = 2x^3y.