((2 - 12 1/2) : (-1/40 + 1/5) + (- (-2) - (-6 2/3)) : (-1 2/3 + 1 5/6)) : 8 = - 1
1) 2 - 12 1/2 = - 10 1/2
2) -1/40 + 1/5 = 1/5 - 1/40 = 8/40 - 1/40 = 7/40
3) -(-2) - (-6 2/3) = 2 + 6 2/3 = 8 2/3
4) -1 2/3 + 1 5/6 = 1 5/6 - 1 2/3 = 1 5/6 - 1 4/6 = 1/6
5) -10 1/2 : 7/40 = -21/2 * 40/7 = - 3/1 * 20/1 = - 60
6) 8 2/3 : 1/6 = 26/3 * 6/1 = 52
7) -60 + 52 = - 8
8) -8 : 8 = -1
((2 - 12 1/2) : (-1/40 + 1/5) + (- (-2) - (-6 2/3)) : (-1 2/3 + 1 5/6)) : 8 = - 1
1) 2 - 12 1/2 = - 10 1/2
2) -1/40 + 1/5 = 1/5 - 1/40 = 8/40 - 1/40 = 7/40
3) -(-2) - (-6 2/3) = 2 + 6 2/3 = 8 2/3
4) -1 2/3 + 1 5/6 = 1 5/6 - 1 2/3 = 1 5/6 - 1 4/6 = 1/6
5) -10 1/2 : 7/40 = -21/2 * 40/7 = - 3/1 * 20/1 = - 60
6) 8 2/3 : 1/6 = 26/3 * 6/1 = 52
7) -60 + 52 = - 8
8) -8 : 8 = -1