What is wrong with this code?

Question

https://code.sololearn.com/cNmEi2P74B6D/?ref=app

Answer 1

Playground\(14,8): error CS0136: A local or parameter named 'x' cannot be declared in this scope because that name is used in an enclosing local scope to define a local or parameter
There was also an error at line 15 very similar to the error statement above.
Translation-
Because you are passing x and y as parameters for the sum method you can't declare x and y inside the sum method. Remove int x; and int y; at lines 14 and 15.

Error codes and statements should be treated as clues to help debug code.

Answer 2

https://code.sololearn.com/cUb78X3gx5mb/?ref=app