Răspuns:
8.
43n ⋮ 3
4+3+n ⋮ 3
7+n ⋮ 3
n = 2, 5, 8
9.
33 × 3³⁰ + 7 × 3³¹ + 3³³
3³⁰ × (33 + 7 × 3¹ + 3³)
3³⁰ × (33 + 21 + 27)
3³⁰ × 81 = (3¹⁵)² × 9² = (3¹⁵ × 9)²