How to work problem x-8=-9

Given :

The librarians need to pack 2 tons of books into cardboard boxes. Each box can safely hold about 25 pounds of books. If they already packed 50 boxes.

To Find :

How many more boxes should they expect to use.

Solution :

We know, 1 ton = 2000 pounds

So, 2 ton = 4000 pounds

Minimum number of boxes required for safe handling :

So, total 160 boxes required.

Therefore, 160 - 50 = 110 many more boxes should they expect to use.

Hence, this is the required solution.