Answer: The required value of x is 30.
Step-by-step explanation: Given that the variables x and y varies directly. And, x = 10 when y = 3.
We are to find the value of x when y = 9.
Given that x and y varies directly. So, we have
![y\propto x\\\\\Rightarrow y=px,~~~~~~~~~~~\textup{[where p is the proportionality constant]}.](https://tex.z-dn.net/?f=y%5Cpropto%20x%5C%5C%5C%5C%5CRightarrow%20y%3Dpx%2C~~~~~~~~~~~%5Ctextup%7B%5Bwhere%20p%20is%20the%20proportionality%20constant%5D%7D.)
When x = 10, y = 3, then

So, the relation between x and y will be

Therefore, when y = 9, then

Thus, the required value of x is 30.