Răspuns :
9 + 9 = 9 × 2
21 + 21 + 21 = 21 × 3
2 + 2 + 2 + 2 = 2 × 4
22 + 22 + 22 = 22 × 3
7 + 7 = 7 × 2
30 + 30 + 30 = 30 × 3
21 + 21 + 21 = 21 × 3
2 + 2 + 2 + 2 = 2 × 4
22 + 22 + 22 = 22 × 3
7 + 7 = 7 × 2
30 + 30 + 30 = 30 × 3