Question

daca A= { x€ Z*|x-1 divide 3} atunci A={...}

Answer 1

D3={-3;-1;1;3}
x - 1 = -3
x = -2

x - 1 = -1
x = 0 ... Nu se adauga la A

x - 1 = 1
x = 2

x - 1 = 3
x = 4

A={-2;2;4}