回答如下:1. (2+3) x 4 - 5 ÷ 10 = 18.5
2. 6 x (8-4) + 3 ÷ 9 = 23.33
3. 7 x 5 + 12 ÷ 4 - 2 = 35
4. (9-3) x 2 + 4 ÷ 8 = 12
5. 15 ÷ (3+1) x 6 - 2 = 16
6. 4 x 7 + 20 ÷ 5 - 1 = 26
7. 10 ÷ 5 x 8 + 6 - 2 = 14
8. (12-4) ÷ 2 x 5 + 3 = 23
9. 9 x 3 ÷ (6-1) + 2 = 5.4
10. 5 + 12 ÷ 4 x 3 - 2 = 9