(8 5/7 - 6 5/6 ÷ 1 5/36) ÷ 4 3/4 =4/7
1)6 5/6 ÷ 1 5/36 = 41/6 ÷ 41/36 = 41/6 × 36/41 = 6
2)8 5/7 - 6 = 61/7 - 6 =(61 × 1 - 6 × 7)/7 = 61/7 - 42/7 = 19/7 = 2 5/7
3)2 5/7 ÷ 4 3/4 = 19/7 ÷ 19/4 = 19/7 × 4/19 = 4/7
(2 5/6 + 2 2/9) ÷ 3 1/4 - 2/7 ÷ 1 7/7 =1 26/63
1)2 5/6 + 2 2/9 = 17/6 + 20/9 = (17 × 3 + 20 × 2)/18 = 51/18 + 40/18 = 91/18 = 5 1/18
2)5 1/18 ÷ 3 1/4 = 91/18 ÷ 13/4 = 91/18 × 4/13 = 14/9 = 1 5/9
3)2/7 ÷ 1 7/7 = 2/7 ÷ 2 = 2/7 × 1/2 = 1/7
4)1 5/9 - 1/7 = 14/9 - 1/7 =(14 × 7 - 1 × 9)/63 = 98/63 - 9/63 = 89/63 = 1 26/63