1:4 - (5 - 7) × 10
2:4 - ((5 - 7) × 10)
3:4 + (7 - 5) × 10
4:4 + ((7 - 5) × 10)
5:4 - (10 × (5 - 7))
6:4 - 10 ×(5 - 7)
7:4 + (10 × (7 - 5))
8:4 + 10 ×(7 - 5)
9:(7 - 5) × 10 + 4
10:((7 - 5) × 10) + 4
11:(10 × (7 - 5)) + 4
12:10 × (7 - 5) + 4
请采纳答案,支持我一下.