Respuesta :
Answer:
21 books need to be moved
Explanation:
123+81=204
204/2=102
So there needs to be 102 books on each shelf.
123-102=21
So 21 books need to be moved from the first shelf.
Answer:
21
Step-by-step explanation:
First we need to find the midpoint.
To find the mid point:
(123+81)÷2=102
So, we need to get both shelfs 102
123-102=21