A book has w chapters. The first chapter is w5 pages long the second chapter is y pages long and the third chapter is w pages long. How many more pages does the second chapter have than the third chapter?
First, we need to find out how many pages are in the book. We know that there are w chapters, and we know that the first chapter is w5 pages long, the second chapter is y pages long, and the third chapter is w pages long. This means that the total number of pages must be w5 + y + w. 

Now, we need to find out how many more pages the second chapter has than the third chapter. To do this, we need to subtract the number of pages in the third chapter from the number of pages in the second chapter. We know that the number of pages in the second chapter is y, and the number of pages in the third chapter is w. This means that the number of pages in the second chapter must be y - w. 

This means that the second chapter has (y - w) more pages than the third chapter.

Therefore, the answer (symbolic expression) is: 

y - w