You didn't include any key information that could help solve this problem. What are the lengths of the books and both shelves?
Equal to, I think. Hope this helps.... If not sorry.
The other number is 3! Hope this helps :)
It has no solution because x is always the same amount. So.. for example.
lets say x = 10.
then it would be 10 + 2 = 10 + 3.
12 doesnt = 13. :)
