Вычислите: (( - 1/225 + 1/30) * 3 6/13 + 4/25) : ( 5/70 + 1/25).

Решим пример по действиям:

1) - 1/225 + 1/30 = - 2/450 + 15/450 = (15 - 2)/450 = 13/450;

2) 13/450 * 3 6/13 = 13/450 * (3 * 13 + 6)/13 = 13/450 * (39 + 6)/13 = 13/450 * 45/13 = 1/10;

3) 1/10 + 4/25 = 5/50 + 8/50 = (5 + 8)/50 = 13/50;

4) 5/70 + 1/25 = 25/350 + 14/350 = (25 + 14)/350 = 39/350;

5) 13/50 : 39/350 = 13/50 * 350/39 = (13 * 350)/(50 * 39) = 7/3.

Ответ: 7/3.