数学题，2，2，7，7怎么算出24？

1: 2 × (7 - 2 + 7)
2: 2 × ((7 - 2) + 7)
3: 2 × (7 - (2 - 7))
4: 2 × (7 + 7 - 2)
5: 2 × ((7 + 7) - 2)
6: 2 × (7 + (7 - 2))
7: (7 - 2 + 7) × 2
8: ((7 - 2) + 7) × 2
9: (7 - (2 - 7)) × 2
10: (7 + 7 - 2) × 2
11: ((7 + 7) - 2) × 2
12: (7 + (7 - 2)) × 2

很容易
（7-2+7）*2=24

(7+7-2)*2=24

2*((7-2)+7）

汗~这么简单都不知道~
7-2=5
5+7=12
2X12=24

一楼对