(7 1/9 - 2 14/15) : (2 2/3 + 1 3/5) - (3/4 - 1/20) * (5/7 - 5/14) = 35/48,
1) 7 1/9 - 2 14/15 = 64/9 - 44/15 = 320/45 - 132/45 = 188/45 = 4 8/45,
2) 2 2/3 + 1 3/5 = 8/3 + 8/5 = 40/15 + 24/15 = 64/15 = 4 4/15,
3) 4 8/45 : 4 4/15 = 188/45 : 64/15 = 188/45 * 15/64 = 47/48,
4) 3/4 - 1/20 = 15/20 - 1/20 = 14/20 = 7/10,
5) 5/7 - 5/14 = 10/14 - 5/14 = 5/14,
6) 7/10 * 5/14 = 1/4,
7) 47/48 - 1/4 = 47/48 - 12/48 = 35/48