4 Вычисли удобным способом: 276 + 49 + 124 5·3·2 325 + 512 + 75 8·4·5 612 – 270 – 312 20·7·5

Ответ: 449, 30, 912, 160, 30, 700

Решим по действиям:

1. 276 + 49 + 124 = (276 + 124) + 49 = 400 + 49 = 449
2. 5 \(\cdot\) 3 \(\cdot\) 2 = 5 \(\cdot\) (3 \(\cdot\) 2) = 5 \(\cdot\) 6 = 30
3. 325 + 512 + 75 = (325 + 75) + 512 = 400 + 512 = 912
4. 8 \(\cdot\) 4 \(\cdot\) 5 = 8 \(\cdot\) (4 \(\cdot\) 5) = 8 \(\cdot\) 20 = 160
5. 612 – 270 – 312 = 612 – (270 + 312) = 612 – 582 = 30
6. 20 \(\cdot\) 7 \(\cdot\) 5 = 20 \(\cdot\) (7 \(\cdot\) 5) = 20 \(\cdot\) 35 = 700

Ответ: 449, 30, 912, 160, 30, 700