Ответ:

Вычислим примеры по порядку:

5 + 8 = 13; 9 + 9 = 18; 12 − 4 = 8; 11 − 9 = 2; 14 − 7 = 7; 12 − 5 = 7; 8 + 3 = 11.

3 + 8 = 11; 6 + 6 = 12; 18 − 9 = 9; 15 − 7 = 8; 6 + 7 = 13; 5 + 9 = 14; 9 + 3 = 12.

68 − 8 = 60; 40 + 5 = 45; 54 − 50 = 4; 47 − 40 = 7; 90 + 6 = 96; 92 − 90 = 2; 38 − 8 = 30.

11 − 8 = 3; 7 + 4 = 11; 17 − 9 = 8; 4 + 8 = 12; 15 − 8 = 7; 13 − 4 = 9; 12 − 6 = 6.