Start with the operation:
The denominator of this fraction is the first number of the code: 5
Now we use the last result to operate:
The denominator of this fraction is the second number of the code: 6
Now we have the horizontal rational operation: 4.7 - 2.8 = 1.9
The integer part of this number is the third number of the code: 1
Finally, we operate:
-5.8 - 2.9 = -8.7
We get the last part of the code: 7
Code: 5617