
With joint variation, though, the variations do not both need to be direct. One

quantity might have direct variation, while the other might have inverse

variation. For example, if x and y had direct variation, they would both

increase, or they would both decrease. And if z varied inversely with x, then if

x increased, z would have to decrease. When setting up the proportion, this

means that since x varies directly with y, they will be directly across from one

another. But since x varies inversely with z, we'll see this z quantity in the

denominator. We flip this fraction. So let's assume this is still true. X is

varying directly with y, and inversely with z. If the value of x is 10 when y

equals 5 and z equals 6. I want you to find the value of x when y is 7 and z is

1. As a hint, this is one case, this x could be 10, this y is 5, and this z is

6. So you try and fill in the other values and then solve for x. And keep in

mind in the setup, we had direct variation with y, so this is directly across

from each other Whereas we had inverse variation with c. This c is a

denominator. Write your answer for x here. You can also think about we're really

finding x too, this value. Good luck.