Which of the following is an equation of joint variation?
y = kxz
x varies with y
y = k/x
y = kx
An equation of joint variation is a mathematical relationship that shows how three variables are related to each other. It can be expressed in the form y = kxz, where y, x, and z are variables, and k is a constant.
Let's look at the given options to see which one represents an equation of joint variation:
1. y = kxz: This equation represents joint variation, as it includes three variables (y, x, and z) multiplied together, with a constant (k) indicating the relationship between them.
2. x varies with y: This is not an equation of joint variation but rather a statement stating that x is dependent on y. It does not provide an equation representing their relationship.
3. y = k/x: This equation represents inverse variation, where y and x are inversely proportional to each other. It is not a joint variation, as it only includes two variables (y and x) and does not include a third variable.
4. y = kx: This equation represents direct variation, where y is directly proportional to x. It is not a joint variation, as it only includes two variables (y and x) and does not include a third variable.
In conclusion, the equation that represents joint variation is y = kxz (Option 1).