2 5/6+(-3 7/8)-(-2 1/12)-1 2 /3

17/6 - 31/8 + 25/12 - 5/3 = (17×4 - 31×3 + 25×2 - 5×8)/24= (68 - 93 + 50 - 40)/24 = - 15/24 = -5/8