а)– (51\6 – 5\6) – (31\6 – 1\6) = б) (3\4 – 2\15) – (1\15 + 1\4) = в)– (3\8 – 5\7) + (7\8 – 5\7) = \-это дробь

а) – (51/6 – 5/6) – (31/6 – 1/6) = – 51/6 + 5/6 – 31/6 + 1/6 = (-51 + 5 - 31 + 1)/6 = -76/6 = -38/3;

Ответ: -38/3.

б) (3/4 – 2/15) – (1/15 + 1/4) = 3/4 – 2/15 – 1/15 - 1/4 = (3 - 1)/4 - (2 + 1)/15 = 2/4 - 3/15 = 1/2 - 1/5 = 5/10 - 2/10 = (5 - 2)/10 = 3/10;

Ответ: 3/10.

в) – (3/8 – 5/7) + (7/8 – 5/7) = – 3/8 + 5/7 + 7/8 – 5/7 = (-3 + 7)/8 + (5 - 5)/7 = 4/8 + 0/7 = 1/2.

Ответ: 1/2.