A = { x ∈ N / 18 I ( x + 1)}
D18 in N ( divizorii lui 18 in multimea nr. naturale, deci N) = { 1,2,3,6,18}
1) x + 1 = 1, rezolvi ecuatia
x = 1 - 1
x = 0 ∈ N, convine
2) x + 1 = 2
x = 2 - 1
x = 1 ∈ N, convine
3) x+ 1 = 3
x = 3 - 1
x = 2 ∈ N, convine
4) x + 1 = 6
x = 6 - 1
x = 5 ∈ N, convine
5) x + 1 = 18
x = 18 - 1
x = 17 ∈ N, convine
A = {0,1,2,5,17}
Sper ca ti-am fost de ajutor!
