а) -(6a-8b)+(14a-7b)-9a = -6a + 8b + 14a - 7b - 9a = -6a + 14a - 9a + 8b - 7b = -a + b
б) 6b-(9a-2b)+(3a-10b) = 6b - 9a + 2b + 3a - 10b = -9a + 3a + 6b + 2b - 10b = -6a - 2b
а) -(6a-8b)+(14a-7b)-9a = -6a + 8b + 14a - 7b - 9a = -6a + 14a - 9a + 8b - 7b = -a + b
б) 6b-(9a-2b)+(3a-10b) = 6b - 9a + 2b + 3a - 10b = -9a + 3a + 6b + 2b - 10b = -6a - 2b