1) <em>91 * 73=5</em>
(9-1)*(7-3) = 8*4 = 32
3 + 2 = 5
2) <em>83 * 96 = 6</em>
(8-3)*(9-6) = 5 * 3 = 15
1 + 5 = 6
3) <em>42 * 61 = 1</em>
(4-2)*(6-1) = 2 * 5 = 10
1 + 0 = 1
4) <em>31 * 82 = ?</em>
(3-1)*(8-2) = 2 * 6 = 12
1 + 2 = 3
Ответ: 31 * 82 = 3