Question

C={x I x ∈N x+5 supra x-1 ∈N}




AJUTOR VA ROG

Answer 1

x+5/x-1€N <=>x-1|x+5(divide)

x-1|x+5

x-1|x-1

Le scadem:

x-1|x+5-x+1 => x-1|6 <=>x-1€D6 in N =>

x-1€{1,2,3,6} =>

x€{2,3,4,7}