2 / 3-6 / 5 + 12 / 7-20 / 9 + 30 / 11-42 / 13 + 56 / 15

2 / 3-6 / 5 + 12 / 7-20 / 9 + 30 / 11-42 / 13 + 56 / 15

The title is wrong
3/2-5/6+7/12-9/20+11/30-13/42+15/56
=1+1/2-1/2-1/3+1/3+1/4…… +1/7+1/8
=1 and 1 / 8

If you can calculate simply, you need to calculate simply (7 / 9-1 / 3) / (1 / 2 × 2 / 3) 3 / 4 [(1 / 3-1 / 6) /
(7 / 9-1 / 3) / (1 / 2 × 2 / 3) 3 / 4 [(1 / 3-1 / 6) / (5)] 3 / 10 (3 / 5-1 / 2) - 5 / 6
(1 / 3-1 / 6-1 / 10) × 30
2 / 15-5 × 4 / 3-7 / 15
6 / 7 × 1 / 13 + 1 / 7 △ 13

(7 / 9-3 / 1) / (1 / 2 × 2 / 3) = (7 / 9-3 / 9) / (1 / 3) = 4 / 9 × 3 = 4 / 3; 3 / 4 ^ [(1 / 3-6 / 1) / (5] = 3 / 4 ^ [(1 / 6) / (5] = 3 / 4 × 6 × 1 / 5 = 9 / 10; 3 / 10 ^ (3 / 5-2 / 1) - 5 / 6 = 3-5 / 6 = 13 / 6