А) (3 целых 1/2 : 4 целых 2/3 +4 целых 2/3 : 3 1/2) ×4 целых4/5

(3 1/2 : 4 2/3 + 4 2/3 : 3 1/2) * 4 4/5 = 10

1) 3 1/2 : 4 2/3 = 7/2 : 14/3 = 7/2 * 3/14 = (1*3)/(2*2) = 3/4
2) 4 2/3 : 3 1/2 = 14/3 : 7/2 = 14/3 * 2/7 = (2*2)/(3*1) = 4/3 = 1 1/3
3) 3/4 + 1 1/3 = 9/12 + 1 4/12 = 1 13/12 = 2 1/12
4) 2 1/12 * 4 4/5 = 25/12 * 24/5 = (5*2)/(1*1) = 10
ответ: 10.

Пояснения:
3 целых 1/2 = (3*2+1)/2 = 7/2
4 целых 2/3 = (4*3+2)/3 = 14/3
3/4 = 9/12 - доп.множ. 3
1/3 = 4/12 - доп.множ. 4
2 целых 1/12 = (2*12+1)/12 = 25/12
4 целых 4/5 = (4*5+4)/5 = 24/5