Question

Enumerati elementele multimilor:
E = { x|x ∈ ℕ,13 < 3x - 5 ≤ 22 }

Answer 1

$13 <3x-5 \leq 22$  | +5

$18 <3x \leq 27$    | :3

$6 <x \leq 9$

E={7; 8; 9}