Solve the following problem:
12−?=15 12-?=15 12−?=15
We know that the distance between 12 and 15 is three steps.
In other words:
12+3=15 12+3=15 12+3=15
Now let's remember the rule:
−(−x)=+ -(-x)=+ −(−x)=+
We'll substitute x with the number 3 and get:
12−(−3)=15 12-(-3)=15 12−(−3)=15
Therefore, the answer is minus 3
−3 -3 −3