Answer:
13
Step-by-step explanation:
The blank space is unknown so we can put in a variable
31 - x - 12 = 6
Then we should try to make it so the variable is on one side and all the numbers on the other
31 - x - 12 = 6
+12 +12
31 - x = 18
-31 -31
-x = -13
×-1 ×-1
x = 13
So your answer would be 13
