Частина 2. Номер 494
6 · 15 = 6 · (10 + 5) = 6 · 10 + 6 · 5 = 60 + 30 = 90;
8 · 11 = 8 · (10 + 1) = 8 · 10 + 8 · 1 = 80 + 8 = 88;
2 · 32 = 2 · (30 + 2) = 2 · 30 + 2 · 2 = 60 + 4 = 64;
4 · 31 = 4 · (30 + 1) = 4 · 30 + 4 · 1 = 120 + 4 = 124;
3 · 23 = 3 · (20 + 3) = 3 · 20 + 3 · 3 = 60 + 9 = 69;
4 · 16 = 4 · (10 + 6) = 4 · 10 + 4 · 6 = 40 + 24 = 64.