a) (5-3b) + (3b - 11) = 5 - 3b + 3b - 11 = (-3+3)b + (5-11) = 0b - 6 = -6
Ответ: $$-6$$
г) (5a - 3b) - (2 + 5a - 3b) = 5a - 3b - 2 - 5a + 3b = (5-5)a + (-3+3)b - 2 = 0a + 0b - 2 = -2
Ответ: $$-2$$