Need solution for Ex 9 pg 94 of Second Edition :Computability, Complexity, and Languages Fundamentals of Theoretical Computer Science Martin D. Davis,Ron Sigal,Elaine J. Weyuker

For every number n, let A = {x I n E W_x}.

(a) Show that A_i is r.e. but not recursive, for all i. (b) Show that A_i =_m A_j for all i, j.