Answer:
I would say that a is NOT an inverse, however b is.
Explanation:
If you look at the two tables for a, you can tell that every pair has swapped places (as they should) except 0 and 9. In which in the second table, what should be the 9 in the x row, is just another 0 in its place.
While if you look at the two tables for b, every single pair has been swapped like it should, meaning the second table is the inverse of the first table.
Hope this helps you btw. I'm sorry if it doesn't though.