5. Вычисли: 7 + 5; 3 + 8; 6 + 5; 8 + 7; 9 + 4; 8 + 4; 7 + 6; 9 + 2; 8 + 6; 9 + 5; 9 + 3; 6 + 6; 9 + 7; 8 + 5; 7 + 4.

Вычисляем суммы:

7 + 5 = 12; 3 + 8 = 11; 6 + 5 = 11; 8 + 7 = 15; 9 + 4 = 13.

8 + 4 = 12; 7 + 6 = 13; 9 + 2 = 11; 8 + 6 = 14; 9 + 5 = 14.

9 + 3 = 12; 6 + 6 = 12; 9 + 7 = 16; 8 + 5 = 13; 7 + 4 = 11.

Ответ: 12, 11, 11, 15, 13, 12, 13, 11, 14, 14, 12, 12, 16, 13, 11.