Answer:
16
Step-by-step explanation:
We know that: 5 + ? = 10.5
we now need to solve for ? , by using the inverse method
10.5 x 2 = 21
21 - 5 = 16
Now to double check the answer, we substitute the ? with the answer
so, 5 + 16 = 21
21/2 = 10.5 so it is clearly correct
I HOPE THIS HELPED :)