5 4/7 / 1 5/21 · (5 2/15 * 3/22 + 1 14/15)= 11,85
1) 5 2/15 · 3/22 = 77/15 · 3/22 = 7/10
2) 7/10 + 1 14/15 = 21/30 + 1 28/30 = 1 49/30 = 2 19/30
3) 5 4/7 / 1 5/21 = 39/7 : 26/21 = 39/7 · 21/26 = 9/2
4) 9/2 · 2 19/30 = 9/2 · 79/ 30 = 237/20 = 11 17/20 = 11,85