1,3,9,10的24点答案：
1:(1 + 10) × 3 - 9
2:((1 + 10) × 3) - 9
3:(3 × (1 + 10)) - 9
4:3 × (1 + 10) - 9
5:(3 × (10 + 1)) - 9
6:3 × (10 + 1) - 9
7:(10 + 1) × 3 - 9
8:((10 + 1) × 3) - 9