(5/7*2 1/3*5/6-1): (1-7/8*1 3/5*3/14)

(5/7×2 1/3×5/6-1)÷(1-7/8×1 3/5×3/14) = 5/9
1)5/7  ×  2 1/3 = 5/7  ×  7/3 =  5/3 = 1 2/3
2)1 2/3  ×  5/6 = 5/3  ×  5/6 =  25/18 = 1 7/18
3) 1 7/18 - 1 = 7/18
4)7/8  ×  1 3/5 = 7/8  ×  8/5 =  7/5 = 1 2/5
5)1 2/5  ×  3/14 = 7/5  ×  3/14 =  3/10
6)1  -  3/10 =(1 × 10  -  3 × 1)/10 = (10  -  3)/10 =  7/10
7) 7/18 ÷ 7/10 = 7/18  ×  10/7 =  5/9