№30. Вычисли. 400 − (80 + 50) + (89 − 9) = ; 0 × 9 + 15 = ; 100 : (90 − 80) × 7 = ; 0 × (18 : 6) = ; 65 : 5 × 4 = ; 90 : 90 × 1 =

1. \(400 - (80 + 50) + (89 - 9) = 400 - 130 + 80 = 350\).
2. \(0 \times 9 + 15 = 0 + 15 = 15\).
3. \(100 : (90 - 80) \times 7 = 100 : 10 \times 7 = 10 \times 7 = 70\).
4. \(0 \times (18 : 6) = 0 \times 3 = 0\).
5. \(65 : 5 \times 4 = 13 \times 4 = 52\).
6. \(90 : 90 \times 1 = 1 \times 1 = 1\).

Ответ: 350; 15; 70; 0; 52; 1.