500 + (600 – 3 × 100) ∶ 10 = 500 + (600 – 300) ∶ 10 = 500 + 300 ∶ 10 = 500 + 30 = 530
9 000 ∶ (100 – 90) ∶ 9 × 2 = 9 000 ∶ 10 ∶ 9 × 2 = 900 ∶ 9 × 2 = 100 × 2 = 200
Ответ: 1) 7; 2) 80; 3) 9; 4) 4; 5) 530; 6) 200