Answer:
To solve the problem, we can use the following steps:
Let the number of blue balls be x.
Then, the number of red balls is also x.
The number of green balls is x + y, where y is some positive integer.
The total number of balls is x + x + (x + y) = 3x + y.
We know that the total number of balls is given as some value, say z.
So, we have 3x + y = z.
This is the equation created to find the number of blue balls.
In summary, the equation to find the number of blue balls is 3x + y = z, where x is the number of blue balls, x is also the number of red balls, y is some positive integer, and z is the total number of balls.