Answer:
5
Step-by-step explanation:
On the LHS (Left Hand Side) 13-6 is 7
So we need to find a number that subtracts into 12 that makes 7 which is 5,
12-5=7
So 5 is the solution
13 - 6 = 7 which is equaled to 12 - 5 = 7
hope this helped :)
