Приведи дроби к общему знаменателю и сделай деянья 1/2-1/8, 1/2-1/3, 5/6-3/8,

1/2 - 1/8 = (1 * 4) / (2 * 4) - 1/8 = 4/8 - 1/8 = (4 - 1) / 8 = 3/8. 

1/2 - 1/3 = (1 * 3) / (2 * 3) - (1 * 2) / (3 * 2) = 3/6 - 2/6 = (3 - 2) / 6 = 1/6.

5/6 - 3/8 = (5 * 4) / (6 *  4) - (3 * 3) / (8 * 3) = 20/24 - 9/24 = (20 - 9) / 24 = 11/24. 

3/4 - 1/12 = (3 * 3) / (4 * 3) - 1/12 = 9/12 - 1/12 = (9 - 1) / 12 = 8/12 = 2/3. 

5/7 - 2/3 = (5 * 3) / (7 * 3)  - (2 * 7) / (3 * 7) = 15/21 - 14/21 = (15 - 14) / 21 = 1/21. 

9/10 - 3/4 = (9 * 2) / (10 * 2) - (3 * 5) / (4 * 5) = 18/20 - 15/20 = (18 - 15) / 20 = 3/20.