1:2 × (7 + 10 ÷ 2)
2:2 × (7 + (10 ÷ 2))
3:2 × (10 ÷ 2 + 7)
4:2 × ((10 ÷ 2) + 7)
5:(7 + 10 ÷ 2) × 2
6:(7 + (10 ÷ 2)) × 2
7:(10 ÷ 2 + 7) × 2
8:((10 ÷ 2) + 7) × 2