8 / 10 + 3 / 30 - 1 / 20 =3 / 12 + 4 / 8 - 1 / 4 =7 / 8 + 2 / 5 - 3 / 4 =7 / 15 + 2 / 3 - 3 / 5 =2 / 3 + 4 / 9 - 1 / 6 =6 / 7 + 4 / 6 - 2 / 3 =?
8 / 10 + 3 / 30 - 1 / 20 = 3 / 12 + 4 / 8 - 1 / 4 = 7 / 8 + 2 / 5 - 3 / 4 = 7 / 15 + 2 / 3 - 3 / 5 = 2 / 3 + 4 / 9 - 1 / 6 = 6 / 7 + 4 / 6 - 2 / 3 =.