To solve this problem, we need to determine the value of x, which represents the number of fish that Agrey caught more than Leo.
We know that Leo caught 40 fish. Therefore, Agrey caught 40 + x fish.
The total number of fish they caught together is 100.
We can set up the equation as follows:
Number of fish caught by Leo + Number of fish caught by Agrey = Total number of fish caught together
40 + (40 + x) = 100
Let's simplify and solve for x:
80 + x = 100
To isolate x, we subtract 80 from both sides of the equation:
80 + x - 80 = 100 - 80
x = 20
The value of x is 20.
#### 20
The answer is: 20
Below is a math problem. Provide a detailed, step-by-step solution.

### Problem:
Leo and Agrey went fishing. Agrey caught x more fish than Leo. If Leo caught 40 fish, The total number of fish they caught together is 100. What is the value of unknown variable x?

### Answer:
