a)A U B = { -5,-2,3,7,9 }
A N B = { 3,7,9 }
A\B = { -2}
b) A U B = { a,b,c,d,m,n,t}
A N B = { b,m,n }
A\B = { a,c}
B\A= { c,t}
d)
N={0,1,2,3,4,5...}
Z={ -infinit,-1,0,1,2,3,4,5...}
A U B = { -infinit -1,0,1,3,4,5,6...+infinit}
A N B = { 0,1,2,3,4,5,6..+infinit}
B\A= { toate numerele negative adică -infinit}