Răspuns :
1+4=5
↓ ↓+7
2+5=12
↓ ↓+9
3+6=21
↓ ↓+11
4+7=32
↓ ↓+13
5+8=45
↓ ↓+7
2+5=12
↓ ↓+9
3+6=21
↓ ↓+11
4+7=32
↓ ↓+13
5+8=45
1 + 4 = 5
2 + 5 = 7 + 5 = 12
3 + 6 = 9 + 12 = 21
4 + 7 = 11 + 21 = 32
5 + 8 = 13 + 32 = 45
6 + 9 = 15 + 45 = 60
2 + 5 = 7 + 5 = 12
3 + 6 = 9 + 12 = 21
4 + 7 = 11 + 21 = 32
5 + 8 = 13 + 32 = 45
6 + 9 = 15 + 45 = 60