3/4:5:6+2цэлых3/4*8= (3цэлых1/2:4цэлых2/3+4цэлых2/3:3цэлых1/2)*4цэлых4/5=

а) 3/4 / 5 / 6 + 2 3/4 * 8 = 22 1/40.
    Преобразуем:
    2 3/4 = (2 * 4 + 3)/4 = 11/4.
    22 = 21 40/40 = (21 * 40 + 40)/40 = 880/40.
    Вычислим:
  1. 3/4 / 5/1 = (3 * 1)/(4 * 5) = 3/20.
  2. 3/20 / 6/1 = (3 * 1)/(20 * 6) = 3/120 = 1/40.
  3. 11/4 * 8 = 88/4 = 22.
  4. 1/40 + 22 = 1/40 + 880/40 = 881/40 = 22 1/40.
б) (3 1/2 / 4 2/3 + 4 2/3 / 3 1/2) * 4 4/5 = 10.
    Преобразуем:
    3 1/2 = (3 * 2 + 1)/2 = 7/2.
    4 2/3 = (4 * 3 + 2)/3 = 14/3.
    4 4/5 = (4 * 5 + 4)/5 = 24/5.
    Вычислим:
  1. 7/2 / 14/3 = (7 * 3)/(2 * 14) = 21/28 сократим на 7 = 3/4.
  2. 14/3 / 7/2 = (14 * 2)/(3 * 7) = 28/21 на 7 = 4/3.
  3. 3/4 + 4/3 = (9 + 16)/12 = 25/12.
  4. 25/12 * 24/5 = (25 * 24)/(12 * 5) = 600/60 = 10.