103. 45 + 23 = ?; 45 + 20 = 65; 65 + 3 = 68; 24 + 24; 32 + 32; 25 + 25; 45 + 45; 72 + 26; 84 + 15; 52 + 36; 46 + 43; 18 + 61; 12 + 88; 65 + 15; 43 + 13.

Разложим 23 на 20 и 3: 45 + 23 = 45 + 20 + 3 = 65 + 3 = 68.

Остальные суммы: 24 + 24 = 48; 32 + 32 = 64; 25 + 25 = 50; 45 + 45 = 90; 72 + 26 = 98; 84 + 15 = 99; 52 + 36 = 88; 46 + 43 = 89; 18 + 61 = 79; 12 + 88 = 100; 65 + 15 = 80; 43 + 13 = 56.

Ответ: 68; 48; 64; 50; 90; 98; 99; 88; 89; 79; 100; 80; 56.