-2+1 7/8, -1+2 1/9, -4+3 1/2 , -5/7+4/7, -5/8+7/8, -1/6+1, 5/12-1/12, 7/15-11/15, 5/16-1/6
- 2 + 1 7/8 = - ( 2 - 1 7/8) = - 1/8 - 1 + 2 1/9 = 2 1/9 - 1 = 1 1/9 - 4 + 3 1/2 =- (4 - 3 1/2) = - 1/2 -5/7 + 4/7 = - (5/7 - 4/7) = - 1/7 -5/8 + 7/8 = 7/8 - 5/8 = 2/8 = 1/4 -1/6 + 1 = 1 - 1/6 = 5/6 5/12 - 1/12 = 4/12 = 1/3 7/15 - 11/15 = - (11-7)/15 = - 4/15 5/16 - 1/6 = 15/48 - 8/48 = 7/48