-1 + (17/24 + 3/8) ÷ 1 5/8 - 5/6 = -1 + (17 + 9/24) ÷ 1 5/8 - 5/6 = -1 + 26/24 ÷ 13/8 - 5/6 = -1 + 26/24 × 8/13 - 5/6 = -1 + 2/3 - 5/6 = -1 + 4-5/6 = -1 - 1/6 = -7/6 = -1 1/6