Выполните действия: 434 ⋅ 31 + 65 ⋅ 17; 179 800 : 29 - 72 ⋅ 78; в) (607 - 427) ⋅ 84 : 36; г) 68 ⋅ (256 + 144) : 340.

Решение:

1. 434 ⋅ 31 + 65 ⋅ 17
• \( 434 \times 31 = 13454 \)
• \( 65 \times 17 = 1105 \)
• \( 13454 + 1105 = 14559 \)
2. 179 800 : 29 - 72 ⋅ 78
• \( 179800 : 29 = 6200 \)
• \( 72 \times 78 = 5616 \)
• \( 6200 - 5616 = 584 \)
3. в) (607 - 427) ⋅ 84 : 36
• \( 607 - 427 = 180 \)
• \( 180 \times 84 = 15120 \)
• \( 15120 : 36 = 420 \)
4. г) 68 ⋅ (256 + 144) : 340
• \( 256 + 144 = 400 \)
• \( 68 \times 400 = 27200 \)
• \( 27200 : 340 = 80 \)

Ответ: 14559; 584; 420; 80.