20/23:2 + (4/15+2/5) : (3*1/3*3/5)

Решаем пример по действиям:

1) 20/23 : 2 = 20 / (23 * 2) = 10/23;

2) 4/15 + 2/5 = 4/15 + 6/15 = (4 + 6) / 15 = 10/15 = 2/3;

3) 3 * 1/3 * 3/5 = (3 * 3) / (3 * 5) = 3/5;

4) 2/3 : 3/5 = 2/3 * 5/3 = (2 * 5) / (3 * 3) = 10/9;

5) 10/23 + 10/9 = 9 * 10/207 + 23 * 10/207 = (90 + 230) / 207 = 320/207;

Ответ: 320/207.