用3.5. 7.11算24点

http://www.dffy.com/tool/24.htm
1: (3 - 7) × (5 - 11)
2: (5 - 11) × (3 - 7)
3: (7 - 3) × (11 - 5)
4: (7 × 11 - 5) ÷ 3
5: ((7 × 11) - 5) ÷ 3
6: (11 - 5) × (7 - 3)
7: (11 × 7 - 5) ÷ 3
8: ((11 × 7) - 5) ÷ 3

(7-3)*(11-5)

(11-5)*(7-3)即可