31/42-(-43/54)-(-79/81)+(-17/63)-(-37/63+67/81)

Question

31/42-(-43/54)-(-79/81)+(-17/63)-(-37/63+67/81)

Answer 1

Раскроем скобки:
= 31/42 + 43/54 + 79/81 - 17/63 + 37/63 - 67/81 = 
= (79/81 - 67/81) + (37/63 - 17/63) + 31/42 + 43/54 =
= 12/81 + 20/63 + 31/42 + 43/54 = 4/27 + 20/63 + 31/42 + 43/54 =
= 56/378 + 120/378 + 279/378 + 301/378 = 756/378 = 2
Ответ: 2.