4. Вычисли: 10 · (20 : 2 - 3) = 100 : (10 · 10) + 81 = 94 - 23 · (47 - 43) = 5 · (21 : 3 - 3) =

Решение:

1. \( 10 \cdot (20 : 2 - 3) = 10 \cdot (10 - 3) = 10 \cdot 7 = 70 \)
2. \( 100 : (10 \cdot 10) + 81 = 100 : 100 + 81 = 1 + 81 = 82 \)
3. \( 94 - 23 \cdot (47 - 43) = 94 - 23 \cdot 4 = 94 - 92 = 2 \)
4. \( 5 \cdot (21 : 3 - 3) = 5 \cdot (7 - 3) = 5 \cdot 4 = 20 \)

Ответ: 70, 82, 2, 20.