共有22种：
1:3 × (4 × (11 - 9))
2:3 × 4 ×(11 - 9)
3:(3 × 4) × (11 - 9)
4:(3 × (11 - 9)) × 4
5:3 × (11 - 9) × 4
6:3 × ((11 - 9) × 4)
7:4 × (3 × (11 - 9))
8:4 × 3 ×(11 - 9)
9:(4 × 3) × (11 - 9)
10:(4 × (11 - 9)) × 3
11:4 × (11 - 9) × 3
12:4 × ((11 - 9) × 3)
13:(9 × 11 - 3) ÷ 4
14:((9 × 11) - 3) ÷ 4
15:(11 - 9) × 3 × 4
16:((11 - 9) × 3) × 4
17:(11 - 9) × (3 × 4)
18:(11 × 9 - 3) ÷ 4
19:((11 × 9) - 3) ÷ 4
20:(11 - 9) × 4 × 3
21:((11 - 9) × 4) × 3
22:(11 - 9) × (4 × 3)