а) 7 9/13-2 5/13+4 2/13 = (7 - 2 + 4) + (9/13 - 5/13 + 2/13) = 9 + 6/13 = 9 6/13
б) 8 8/21-(5 5/21-3 2/21) = 176/21 - (110/21 - 65/21) = 176/21 - 15/7 = 131/21 =
= 6 5/21
а) 7 9/13-2 5/13+4 2/13 = (7 - 2 + 4) + (9/13 - 5/13 + 2/13) = 9 + 6/13 = 9 6/13
б) 8 8/21-(5 5/21-3 2/21) = 176/21 - (110/21 - 65/21) = 176/21 - 15/7 = 131/21 =
= 6 5/21