а) 9,5m + 3m = 12,5m.
б) 6b – b = 5b.
в) a - \(\frac{2}{3}a = \frac{1}{3}a\).
г) \(\frac{5}{7}m - m = -\frac{2}{7}m\).
д) 1,2y + 3,6y – 0,7y = 4,1y.
е) \(\frac{4}{9}a + \frac{2}{9}a - \frac{1}{3}a = \frac{6}{9}a - \frac{1}{3}a = \frac{2}{3}a - \frac{1}{3}a = \frac{1}{3}a\).
ж) -4x – x + 3 = -5x + 3.
з) 7x – 6y – 2x + 8y = (7x – 2x) + (-6y + 8y) = 5x + 2y.