正文

1. 5 + 8 × 3 - 2 ÷ 4 2. 12 ÷ 2 × 6 + 3 - 9 3. 7 × 4 + 5 × 2 - 3 ÷ 1 4. 6 × (7 + 2) - 4 ÷ 2 5. 9 + 3 × 4 - 2 × 5 6. 15 ÷ 3 + 6 × 2 - 8 7. 8 × (5 - 2) + 3 ÷ 1 8. 4 × 6 + 7 ÷ 2 - 3 9. 12 ÷ (3